Trushape · Dimensional tolerances

Casting tolerances you can design to, measured, not estimated.

Trushape holds investment castings to VDG P690 grade D2 as standard, ±0.31 mm on a 30 to 50 mm dimension, and shell, die and sand castings to ISO 8062-3 grades, with critical dimensions measured on a Zeiss CMM, for buyers across North America and Europe.

Find your tolerance Exporting to North America and Europe

VDG P690 D1 to D3 ISO 8062-3 DCTG 5 to 14 Millimetres and inches Zeiss CMM and Keyence VMM

VDG P690 D1, D2, D3
ISO 8062-3 DCTG
RMA grades A to K
ASME Y14.5
ISO 1101 and ISO 5459
3-2-1 datum targets
Zeiss CMM
Keyence VMM
First article inspection
Millimetres and inches
CT5 to CT7 investment castings
EN 10204 3.1

At a glance

How accurate is a casting, and how do you specify it?

Casting dimensional tolerances say how far a cast dimension may vary from its nominal size. They are set by grade: VDG P690 grades D1 to D3 for investment castings, and ISO 8062-3 dimensional casting tolerance grades, DCTG 1 to 16, for every casting process. The tolerance grows with the size of the dimension, and features that need more accuracy than the process gives are machined.

Trushape Precision Castings is an ISO 9001, ISO 14001, ISO 45001 and ISO 13485 certified foundry in Bhavnagar, Gujarat, India. We hold investment and rapid castings to VDG P690 D2 as standard, about DCTG 5 to 7, gravity die castings to DCTG 7 to 9, shell moldings to DCTG 8 to 12, and lost foam and no-bake castings to DCTG 11 to 14, then machine critical features and measure them on a Zeiss CMM for buyers across the United States, Canada, Mexico, the United Kingdom and the European Union.

Casting processes, each with its grade

ISO 8062-3 tolerance grades

CNC machines for critical features

ISO certifications

From drawing to report

How a tolerance is held and proven, in six steps

Follow one flanged casting from the numbers on its drawing to the report that ships with it. The tolerance is designed into the tool, cast, measured against your datums and finished by machining where it matters.

Step 01 · Specify

The drawing sets the numbers

It starts with your drawing: nominal sizes, a general tolerance grade, the few dimensions that need more, and datums A, B and C that casting, machining and inspection all measure from.

General tolerance, for example VDG P690 D2
Datum targets agreed before tooling

Step 02 · Tool

An oversize tool, on purpose

Metal shrinks as it cools, so the wax die is cut larger than the part by the contraction allowance, about 2% for steel. The allowance depends on alloy, shape and process, and is proven on first-off samples.

Contraction allowance built into the die
Proven on first-off samples

Step 03 · Cast

Cast hot, then shrink to size

The casting leaves the mould hot and oversize, then contracts as it cools. With the right allowance it lands on its nominal size, inside the tolerance band of its grade.

Steel contracts about 2% on cooling
Lands inside the tolerance band

Step 04 · Align

Datums first, on the CMM

On the Zeiss CMM the stylus touches three points on datum A, two on datum B and one on datum C. That fixes the part's coordinates, so every measurement follows your drawing, not the way the part happens to sit.

3-2-1 alignment to your datums
Zeiss coordinate measuring machine

Step 05 · Measure

Every critical feature, measured

Flange, body and hole positions are probed and compared with the CAD model and the tolerance of each dimension. The deviation map shows where metal sits over or under nominal, each point inside its band.

Keyence VMM for small features
First article and in-process checks

Step 06 · Report

Machined where it matters, then reported

Bores and seal faces that need more than the casting grade are machined on our CNC machines. The dimensional report is issued against your drawing and ships with the parts and the EN 10204 3.1 material certificate.

8 CNC, two 4-axis Makino VMCs
Report against your drawing

Tolerance calculator

What tolerance will your dimension hold?

Pick a process, enter a nominal size in millimetres or inches and choose a grade. The calculator reads the same VDG P690 and ISO 8062-3 tables printed below, and the 3D chart places your answer among all sixteen ISO grades.

Tolerance tables

VDG P690 and ISO 8062-3 tables, in full

The tables our engineers quote from, in millimetres and inches. The standards list total tolerances, the full width of the band. Placed evenly around the nominal size, half goes each way, so 0.62 mm in total means ±0.31 mm.

VDG P690 for investment castings in steel, nickel, cobalt and copper alloys (material group D)

VDG P690 linear tolerances for investment castings in material group D, steel, nickel, cobalt and copper alloys: plus or minus value, total tolerance and equivalent ISO 8062-3 grade, by nominal size and accuracy grade
Nominal size (mm)	Nominal size (in)	D1, free	D2, standard	D3, agreed
Up to 6	Up to 0.24	±0.150.30 total, DCTG 5	±0.120.24 total, DCTG 4	±0.100.20 total, DCTG 4
6 to 10	0.24 to 0.39	±0.180.36 total, DCTG 5	±0.140.28 total, DCTG 5	±0.110.22 total, DCTG 4
10 to 18	0.39 to 0.71	±0.220.44 total, DCTG 6	±0.170.34 total, DCTG 5	±0.140.28 total, DCTG 4
18 to 30	0.71 to 1.18	±0.260.52 total, DCTG 6	±0.200.40 total, DCTG 5	±0.170.34 total, DCTG 5
30 to 50	1.18 to 1.97	±0.400.80 total, DCTG 7	±0.310.62 total, DCTG 6	±0.250.50 total, DCTG 5
50 to 80	1.97 to 3.15	±0.450.90 total, DCTG 7	±0.370.74 total, DCTG 6	±0.300.60 total, DCTG 6
80 to 120	3.15 to 4.72	±0.551.1 total, DCTG 7	±0.440.88 total, DCTG 6	±0.350.70 total, DCTG 6
120 to 180	4.72 to 7.09	±0.801.6 total, DCTG 8	±0.651.3 total, DCTG 7	±0.501 total, DCTG 6
180 to 250	7.09 to 9.84	±1.202.4 total, DCTG 9	±0.951.9 total, DCTG 8	±0.751.5 total, DCTG 8
250 to 315	9.84 to 12.40	±1.302.6 total, DCTG 9	±1.102.2 total, DCTG 8	±0.801.6 total, DCTG 7
315 to 400	12.40 to 15.75	±1.803.6 total, DCTG 10	±1.402.8 total, DCTG 9	n/a
400 to 500	15.75 to 19.69	±2.004 total, DCTG 10	±1.603.2 total, DCTG 9	n/a
500 to 630	19.69 to 24.80	±2.705.4 total, DCTG 11	±2.204.4 total, DCTG 10	n/a
630 to 800	24.80 to 31.50	±3.106.2 total, DCTG 11	±2.505 total, DCTG 10	n/a
800 to 1,000	31.50 to 39.37	±3.607.2 total, DCTG 11	n/a	n/a

D1 is the free tolerance for every dimension without its own tolerance. D2 applies to toleranced dimensions and is our standard. D3 applies only to dimensions agreed with the foundry, because it needs extra process steps and tooling adjustment. Each cell gives the ± value, then the total and the equivalent ISO 8062-3 grade. n/a: not defined at this size.

VDG P690 for aluminium and magnesium investment castings (material group A)

VDG P690 linear tolerances for investment castings in material group A, aluminium and magnesium alloys, by nominal size and accuracy grade
Nominal size (mm)	Nominal size (in)	A1, free	A2, standard	A3, agreed
Up to 6	Up to 0.24	±0.150.30 total, DCTG 5	±0.120.24 total, DCTG 4	±0.100.20 total, DCTG 4
6 to 10	0.24 to 0.39	±0.180.36 total, DCTG 5	±0.140.28 total, DCTG 5	±0.110.22 total, DCTG 4
10 to 18	0.39 to 0.71	±0.220.44 total, DCTG 6	±0.170.34 total, DCTG 5	±0.140.28 total, DCTG 4
18 to 30	0.71 to 1.18	±0.260.52 total, DCTG 6	±0.200.40 total, DCTG 5	±0.170.34 total, DCTG 5
30 to 50	1.18 to 1.97	±0.400.80 total, DCTG 7	±0.310.62 total, DCTG 6	±0.250.50 total, DCTG 5
50 to 80	1.97 to 3.15	±0.450.90 total, DCTG 7	±0.370.74 total, DCTG 6	±0.300.60 total, DCTG 6
80 to 120	3.15 to 4.72	±0.551.1 total, DCTG 7	±0.440.88 total, DCTG 6	±0.350.70 total, DCTG 6
120 to 180	4.72 to 7.09	±0.801.6 total, DCTG 8	±0.651.3 total, DCTG 7	±0.501 total, DCTG 6
180 to 250	7.09 to 9.84	±0.951.9 total, DCTG 8	±0.751.5 total, DCTG 8	±0.601.2 total, DCTG 7
250 to 315	9.84 to 12.40	±1.302.6 total, DCTG 9	±1.102.2 total, DCTG 8	±0.801.6 total, DCTG 7
315 to 400	12.40 to 15.75	±1.402.8 total, DCTG 9	±1.202.4 total, DCTG 9	±0.851.7 total, DCTG 8
400 to 500	15.75 to 19.69	±1.603.2 total, DCTG 9	±1.302.6 total, DCTG 8	±0.951.9 total, DCTG 8
500 to 630	19.69 to 24.80	±2.204.4 total, DCTG 10	±1.703.4 total, DCTG 9	n/a
630 to 800	24.80 to 31.50	±2.505 total, DCTG 10	±2.004 total, DCTG 9	n/a
800 to 1,000	31.50 to 39.37	±2.805.6 total, DCTG 10	±2.304.6 total, DCTG 10	n/a
1,000 to 1,250	39.37 to 49.21	±3.306.6 total, DCTG 10	n/a	n/a

Grades A1 to A3 follow the same logic as D1 to D3. VDG P690 also defines grades T1 to T3 for titanium alloys.

ISO 8062-3 dimensional casting tolerance grades, DCTG 1 to 16

ISO 8062-3 total dimensional casting tolerances in millimetres for grades DCTG 1 to 16, by nominal dimension
Nominal size (mm)	Nominal size (in)	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Up to 10	Up to 0.39	0.09	0.13	0.18	0.26	0.36	0.52	0.74	1	1.5	2	2.8	4.2	n/a	n/a	n/a	n/a
10 to 16	0.39 to 0.63	0.10	0.14	0.20	0.28	0.38	0.54	0.78	1.1	1.6	2.2	3	4.4	n/a	n/a	n/a	n/a
16 to 25	0.63 to 0.98	0.11	0.15	0.22	0.30	0.42	0.58	0.82	1.2	1.7	2.4	3.2	4.6	6	8	10	12
25 to 40	0.98 to 1.57	0.12	0.17	0.24	0.32	0.46	0.64	0.90	1.3	1.8	2.6	3.6	5	7	9	11	14
40 to 63	1.57 to 2.48	0.13	0.18	0.26	0.36	0.50	0.70	1	1.4	2	2.8	4	5.6	8	10	12	16
63 to 100	2.48 to 3.94	0.14	0.20	0.28	0.40	0.56	0.78	1.1	1.6	2.2	3.2	4.4	6	9	11	14	18
100 to 160	3.94 to 6.30	0.15	0.22	0.30	0.44	0.62	0.88	1.2	1.8	2.5	3.6	5	7	10	12	16	20
160 to 250	6.30 to 9.84	n/a	0.24	0.34	0.50	0.70	1	1.4	2	2.8	4	5.6	8	11	14	18	22
250 to 400	9.84 to 15.75	n/a	n/a	0.40	0.56	0.78	1.1	1.6	2.2	3.2	4.4	6.2	9	12	16	20	25
400 to 630	15.75 to 24.80	n/a	n/a	n/a	0.64	0.90	1.2	1.8	2.6	3.6	5	7	10	14	18	22	28
630 to 1,000	24.80 to 39.37	n/a	n/a	n/a	n/a	1	1.4	2	2.8	4	6	8	11	16	20	25	32

Total tolerance in mm. On typical dimensions our investment and rapid castings sit at about DCTG 5 to 7 (through VDG P690), gravity die castings at DCTG 7 to 9, shell moldings at DCTG 8 to 12, and lost foam and no-bake sand castings at DCTG 11 to 14. Wall thicknesses take one grade coarser. Grades 13 to 16 give no general value up to 16 mm, so those dimensions need their own tolerance, and grade 16 applies only to wall thicknesses of castings toleranced to DCTG 15.

ISO 8062-3 required machining allowance per machined surface, grades A to K

ISO 8062-3 required machining allowance in millimetres per machined surface, grades A to K, by largest overall dimension of the casting
Largest dimension (mm)	Largest dimension (in)	A	B	C	D	E	F	G	H	J	K
Up to 40	Up to 1.57	0.1	0.1	0.2	0.3	0.4	0.5	0.5	0.7	1	1.4
40 to 63	1.57 to 2.48	0.1	0.2	0.3	0.3	0.4	0.5	0.7	1	1.4	2
63 to 100	2.48 to 3.94	0.2	0.3	0.4	0.5	0.7	1	1.4	2	2.8	4
100 to 160	3.94 to 6.30	0.3	0.4	0.5	0.8	1.1	1.5	2.2	3	4	6
160 to 250	6.30 to 9.84	0.3	0.5	0.7	1	1.4	2	2.8	4	5.5	8
250 to 400	9.84 to 15.75	0.4	0.7	0.9	1.3	1.8	2.5	3.5	5	7	10
400 to 630	15.75 to 24.80	0.5	0.8	1.1	1.5	2.2	3	4	6	9	12
630 to 1,000	24.80 to 39.37	0.6	0.9	1.2	1.8	2.5	3.5	5	7	10	14

Allowance in mm on each surface to be machined. Read the row from the largest overall dimension of the finished casting, not from the feature being machined, so a 25 mm bore in a 120 mm casting takes the 100 to 160 mm row. Investment castings typically take grade E. A drawing note reads, for example, ISO 8062-3 DCTG 12, RMA 6 (RMAG H) for a 400 to 630 mm casting.

Process comparison

One dimension, six processes, side by side

The same nominal size cast six ways. Each slab is the band a process holds around nominal: the solid core is its tightest grade and the pale edge its loosest. Pick a size and watch the bands grow, or pick a process to read it.

VDG P690 D1 to D3

Investment casting

A ceramic shell built around a wax pattern copies the die closely, so investment castings are the most accurate as cast. D2 is our standard, and D3 is agreed on the features that need it.

At 50 mm: ±0.25 to ±0.40 mm
About DCTG 5 to 7 on typical dimensions
0.003 to 30 kg (0.1 oz to 66 lb)

Investment casting

VDG P690, agreed per drawing

Rapid manufacturing

3D-printed patterns run through the same investment casting line and typically hold the same grades. Printed patterns vary more than wax, so we confirm the tolerances against your drawing first.

At 50 mm: ±0.25 to ±0.40 mm
No hard tooling, first metal in weeks
0.005 to 30 kg (0.2 oz to 66 lb)

Rapid manufacturing

ISO 8062-3 DCTG 7 to 9

Gravity die casting

Metal dies filled by gravity repeat closely from casting to casting, the tightest of the processes toleranced to ISO 8062-3.

At 50 mm: ±0.50 to ±1.00 mm
Copper, aluminium and zinc alloys
0.1 to 3 kg (0.2 to 6.6 lb)

Gravity die casting

ISO 8062-3 DCTG 8 to 12

Shell molding

Resin sand shells formed on heated metal patterns give accurate, repeatable sand castings, much closer than conventional sand moulds.

At 50 mm: ±0.70 to ±2.80 mm
Steels and copper alloys
5 to 60 kg (11 to 132 lb)

Shell molding

ISO 8062-3 DCTG 11 to 14

Lost foam casting

A foam pattern in unbonded sand makes large, complex castings with no cores or parting lines, where machining stock covers the wider band.

At 50 mm: ±2.00 to ±5.00 mm
Steels, copper and aluminium alloys
3.5 to 90 kg (7.7 to 198 lb)

Lost foam casting

ISO 8062-3 DCTG 11 to 14

No-bake sand casting

Chemically bonded sand moulds suit larger, lower-volume castings. Functional faces are machined, and the rest stays within the sand casting grade.

At 50 mm: ±2.00 to ±5.00 mm
Steels, copper and aluminium alloys
3 to 40 kg (6.6 to 88 lb)

All casting processes

As-cast tolerance, tightest to loosest grade, for each casting process at 25, 50, 100 and 250 mm
Process	Standard and grades	At 25 mm (1.0 in)	At 50 mm (2.0 in)	At 100 mm (3.9 in)	At 250 mm (9.8 in)
Investment casting	VDG P690 D1 to D3, D2 standard	±0.17 to ±0.26	±0.25 to ±0.40	±0.35 to ±0.55	±0.75 to ±1.20
Rapid manufacturing	VDG P690, as investment casting	±0.17 to ±0.26	±0.25 to ±0.40	±0.35 to ±0.55	±0.75 to ±1.20
Gravity die casting	ISO 8062-3 DCTG 7 to 9	±0.41 to ±0.85	±0.50 to ±1.00	±0.55 to ±1.10	±0.70 to ±1.40
Shell molding	ISO 8062-3 DCTG 8 to 12	±0.60 to ±2.30	±0.70 to ±2.80	±0.80 to ±3.00	±1.00 to ±4.00
Lost foam casting	ISO 8062-3 DCTG 11 to 14	±1.60 to ±4.00	±2.00 to ±5.00	±2.20 to ±5.50	±2.80 to ±7.00
No-bake sand casting	ISO 8062-3 DCTG 11 to 14	±1.60 to ±4.00	±2.00 to ±5.00	±2.20 to ±5.50	±2.80 to ±7.00

Investment and rapid castings use VDG P690 D3 to D1, material group D; the other processes use the ISO 8062-3 DCTG range shown. The grade of a given feature depends on its size, the alloy and the shape of the part.

A drawing names a number. A foundry has to hold it, measure it and prove it. So we agree the grade before we cut the tool, measure from your datums and machine only where the casting cannot reach.

Form and position

GD&T on castings, one zone at a time

Size is only half of a drawing. Geometric tolerances to ASME Y14.5 or ISO 1101 limit form, orientation and position, each as a zone the real surface or axis must stay inside. Pick a control to see its zone in 3D, drawn larger than life so it can be seen.

Form, no datum

Flatness

Every point of the surface must lie between two parallel planes set the tolerance apart. Flatness controls form only, so it needs no datum.

How we check itCMM points or a surface scan across the face
Casting tipLong thin plates move as they cool; ribs or a machined face keep a sealing surface flat

Form, no datum

Straightness

A line on the surface, or the median line of a shaft, must stay inside the zone; with a diameter sign the zone is a cylinder around the axis.

How we check itCMM sections along the length of the feature
Casting tipEven sections cool evenly, which keeps long features straight

Form, no datum

Circularity

Each cross-section of a round feature must lie between two concentric circles, the tolerance apart.

How we check itCMM circles at several heights
Casting tipRound bores that seal or fit are usually machined; as-cast circularity suits clearance features

Orientation, datum A

Parallelism

The surface must lie between two planes parallel to datum A, the tolerance apart, so it controls tilt and flatness together.

How we check itAligned to datum A on the CMM, then probed across the face
Casting tipChoose a large, stable as-cast face for datum A, away from gates and parting lines

Orientation, datum A

Perpendicularity

The axis of a boss or bore must stay inside a cylinder standing square to datum A.

How we check itA cylinder fitted by the CMM, measured against datum A
Casting tipMachining the face and the bore in one set-up gives the tightest result

Location, datums A, B and C

Position

A hole's axis must stay inside a cylindrical zone centred on its true position, located by basic dimensions from datums A, B and C.

How we check itCMM against datums A, B and C, the same way the part is assembled
Casting tipAs-cast holes suit clearance; holes for fits or threads are drilled or bored on our CNC machines

The values in the frames are examples. ISO 8062-3 also defines general geometrical casting tolerance grades, GCTG, for straightness, flatness, circularity, parallelism, perpendicularity, symmetry and coaxiality; the grade or the values on your drawing always apply.

Design for accuracy

Eight drawing habits that make tolerances easy to hold

Most tolerance trouble starts on the drawing. These are the points our engineers check first when they review a new part, from datums to machining stock. Hover or tap a card to turn it over.

Mark 3-2-1 datum targets

Datums. Three targets on the primary face, two on the secondary and one on the tertiary, on as-cast surfaces away from gates, so every step measures from the same places.

Tighten only what matters

Tolerances. Let a general grade such as VDG P690 D2 cover most dimensions. Tighter values add process steps, so keep them for functional features and machine where needed.

Cast holes to a depth rule

Holes. Without cores, VDG P690 suggests through holes about 3 × d deep for 6 to 10 mm holes and 4 × d above 10 mm, with blind holes about half as deep.

Radius every inside corner

Inner radii. Make inner radii at least 20% of the thickest wall and never under 0.5 mm, ideally no smaller than the thinnest wall. Fillets help metal flow and lower stress.

Give edge radii as a maximum

Outer edges. An as-cast edge is never perfectly sharp, so outer radii and chamfers are called out as a maximum, such as R0.5 max.

Allow for wall tolerance

Walls. In VDG P690 a wall varies with the smallest side of its surface, from ±0.25 mm up to 50 mm to ±0.50 mm at 180 to 315 mm. In ISO 8062-3 walls take one grade coarser.

Size the stock by the part

Machining. Machining allowance comes from the largest dimension of the casting. Mark only the faces, bores and threads to be machined, and leave the rest as-cast.

Name the finish you need

Surface. VDG P690 makes N9, Ra 6.3 µm (250 µin) shot-blasted, the standard delivery; N8, Ra 3.2 µm, and N7, Ra 1.6 µm, are agreed separately.

The numbers behind the rules, from VDG P690

Radius tolerance
Radius (mm)	Grade 1	Grade 2	Grade 3
Up to 5	±0.30	±0.20	±0.15
5 to 10	±0.45	±0.35	±0.25
10 to 120	±0.70	±0.50	±0.40
Over 120	Linear tolerance applies

Wall thickness tolerance
Smallest side of the surface (mm)	Groups D and A
Up to 50	±0.25
50 to 100	±0.30
100 to 180	±0.40
180 to 315	±0.50
Over 315	±0.60

Holes cast without cores
Diameter d (mm)	Through, max depth	Blind, max depth
2 to 4	About 1 × d	About 0.6 × d
4 to 6	About 2 × d	About 1 × d
6 to 10	About 3 × d	About 1.6 × d
Over 10	About 4 × d	About 2 × d

From VDG P690 for investment castings. Deeper holes, slots and passages are made with ceramic cores or machined. Titanium castings, group T, have slightly wider wall tolerances.

How we measure

Measured against your drawing and datums

A tolerance is only as good as the measurement behind it. Critical dimensions are checked on calibrated equipment against your datums, and the results travel with the parts.

CMM

Zeiss CMM

Three-dimensional measurement of datums, sizes and positions against your CAD model and drawing.

VMM

Keyence VMM

Fast optical measurement of profiles, small holes, radii and edges.

SCAN

3D scanning

Full-surface comparison with CAD during development and reverse engineering.

FAI

First article inspection

Every dimension on the drawing measured on the first parts, before series production.

IPC

In-process checks

Critical dimensions checked during production runs, not only at the end.

3-2-1

Datum alignment

Parts aligned to your datum targets A, B and C before anything is measured.

CNC

CNC finishing

Eight CNC machines, including two 4-axis Makino VMCs, for bores, faces and threads.

DOC

Dimensional reports

Measured values against nominal and tolerance, kept with the heat number of the parts.

Documentation with every shipment

Dimensional and first article reports against your drawing, material certificates to EN 10204 3.1 as standard and 3.2 when your order calls for independent inspection, and NDT reports where required, all traceable to the heat number.

Dimensional reports First article reports EN 10204 3.1 and 3.2 certificates Heat-number traceability NDT reports on request Millimetre or inch units

Standards and certifications

Toleranced to the standards on your drawing

We read and work to the tolerancing standards common on North American and European drawings, from the casting grades themselves to GD&T, fits and surface texture.

Casting tolerancesISO 8062-3:2023General dimensional and geometrical tolerances and machining allowance grades for castings: DCTG, GCTG and RMAG.

Investment castingsVDG P690The German guideline for tolerances, surface condition and machining allowance of investment castings, grades D1 to D3.

GD&T, North AmericaASME Y14.5Dimensioning and tolerancing on North American drawings: datums, form, orientation, profile and position.

GD&T, ISO drawingsISO 1101, ISO 5459Geometrical tolerancing, and the datums and datum systems it refers to.

Machined featuresISO 2768General tolerances for machined sizes and geometry where the drawing gives none, such as ISO 2768-mK.

FitsISO 286Limits and fits for machined bores and shafts, such as H7 and g6.

Surface textureISO 21920-1Surface texture on drawings, such as Ra and Rz; it replaced ISO 1302 in 2021.

Inspection documentsEN 10204Material certificates: type 3.1 as standard, and 3.2 with independent inspection when your order requires it.

Quality managementISO 9001:2015A certified quality system, TUV INDIA, under which our measuring equipment is calibrated and every order is controlled.

ISO 9001:2015Quality, TUV INDIA

ISO 14001:2015Environment, TUV NORD

ISO 45001:2018Health and safety, TUV NORD

ISO 13485:2016Medical devices, DNV

What we certify, and what we promise

Trushape holds ISO 9001, ISO 14001, ISO 45001 and ISO 13485. We do not hold AS9100, IATF 16949, PED or ASME approvals. Tolerances are agreed per drawing: we quote the grade a process can hold, agree D3 or tighter values only on the features that need them, and prove them on first-off samples before series production.

Download our certificates

North America and Europe

Tolerances that read the same in Chicago and Stuttgart

An export-focused foundry with a dedicated export desk, already shipping castings to Germany, the UK, Belgium, Denmark, Spain and Italy. We read inch and metric drawings, ASME and ISO alike. Pick a region to trace the lane from Bhavnagar.

United States: Chicago and the Great Lakes

Pump, valve, machinery and vehicle makers from Chicago to Cleveland, drawing in inches to ASME Y14.5.

Canada: Ontario and Quebec

Machinery, energy and transport manufacturers around Toronto and Montreal.

Mexico: Monterrey and the Bajío

Nearshore manufacturers in Nuevo León and Querétaro that need castings measured to the drawing.

United Kingdom: The Midlands and the South West

Engineering, pump and valve companies around Birmingham and Bristol.

Germany: Stuttgart and Munich

Machinery, automotive and instrument makers who specify VDG P690 and ISO GPS tolerances.

Netherlands and France: Eindhoven to Lyon

High-tech equipment, valve and process builders from Brainport Eindhoven to the Lyon region.

Sweden and Italy: Gothenburg to Turin

Vehicle, bearing and machinery makers around Gothenburg and Turin.

Series parts travel by sea freight in export packing, and urgent samples by air. Delivery terms and documentation are agreed with our export desk for each order, and every shipment carries English dimensional reports and certificates.

Where tolerance matters

The critical features of the parts we cast

Drag the ring or let it turn. Each card pairs a part family with the features that carry its tolerance, and how we usually hold them: as cast, or machined.

Valve bodies

CriticalSeat bore, flange faces

ApproachCast near size, seats machined

Flange holes cast or drilled to true position.

Pump impellers

CriticalVane profile, hub bore

ApproachVanes as cast, hub bored

Investment cast vanes keep the hydraulic profile.

Pump casings

CriticalVolute, mounting faces

ApproachVolute as cast, faces machined

Datums on the flange keep machining aligned.

Gearbox housings

CriticalBearing bores

ApproachBores machined to fit

Stock only where the bearings sit.

Brackets and levers

CriticalPivot holes, mounting pads

ApproachProfile as cast, holes reamed

One casting can replace a welded assembly.

Medical instrument parts

CriticalSmall features, fine edges

ApproachClose as cast, D3 agreed

From an ISO 13485 certified foundry.

Textile machine parts

CriticalSlots and pin holes

ApproachSlots cast, holes drilled

Repeatable parts for long production runs.

Hardware and fittings

CriticalVisible faces, threads

ApproachFaces as cast, threads machined

Consistent size for plating and assembly.

Optical and sighting housings

CriticalDatum faces, bores

ApproachDatum faces machined

Measured on the CMM from the mounting datums.

Manifold blocks

CriticalPort positions, sealing faces

ApproachPassages cored, ports machined

Internal passages cast in with ceramic cores.

Burner and nozzle parts

CriticalOrifices, seating faces

ApproachNear net shape, seats finished

Cast in heat-resistant nickel and cobalt alloys.

Marine bushings

CriticalBore and outside diameter

ApproachCast with stock, finish turned

Stock sized by ISO 8062-3 machining allowance.

Why Trushape

Accuracy you can document

Engineers and buyers in North America and Europe bring their tolerance-critical parts to us for the same six reasons.

Two standards, one scale

VDG P690 for investment and rapid castings, ISO 8062-3 for shell, die and sand castings, both read on the same DCTG scale.

Clear grades

Datums agreed up front

Datum targets are agreed before the tool is cut, so casting, machining and inspection all start from the same points.

3-2-1

Measured, not estimated

Zeiss CMM and Keyence VMM, first article inspection and in-process checks on critical dimensions.

Metrology

Machined in-house

Eight CNC machines, including two 4-axis Makino VMCs, finish what the casting grade cannot reach.

8 CNC

Honest grades

We quote the grade a process can hold, and agree D3 or tighter values only where a feature needs them.

No surprises

Reports you can audit

Dimensional reports against your drawing, with EN 10204 3.1 material certificates and heat-number traceability.

Full records

A short history of accuracy

How tolerances became a shared language

Today's casting grades rest on more than a century of measurement, from the first gauge blocks to coordinate measuring machines and the GPS standards.

1896
Gauge blocks
Carl Edvard Johansson makes the first sets of precision gauge blocks in Sweden, giving workshops a shared reference for length.
1940
True position
Stanley Parker, at the Royal Torpedo Factory in Scotland, shows that a round tolerance zone suits hole positions better than a square one, a root of modern GD&T.
1959
The first CMM
Ferranti shows the first coordinate measuring machine at the International Machine Tool Exhibition in Paris.
1966
GD&T is standardised
The first Y14.5 standard is published in the United States; today's ASME Y14.5 grew from it.
1994
One system for castings
ISO 8062 sets out tolerance grades and machining allowance grades for castings made by any process.
2007
Castings join the GPS system
ISO 8062-3 brings dimensional and geometrical casting tolerance grades, DCTG and GCTG, into the GPS family of standards.
2023
ISO 8062-3 revised
A new edition of ISO 8062-3 is published, the version in use today.
TODAY
Measured, not estimated
Trushape casts to these grades in six processes and checks critical dimensions on a Zeiss CMM before parts ship.

FAQ

Casting tolerances: questions engineers ask

What tolerances can investment castings hold?

Our investment castings are held to VDG P690, the German standard for investment castings. Its standard grade, D2, allows 0.62 mm in total on a 30 to 50 mm dimension, ±0.31 mm, which equals ISO 8062-3 DCTG 6. D1 applies where the drawing gives no tolerance, and the tightest grade, D3, reaches ±0.10 mm on agreed features up to 6 mm.

What is the difference between VDG P690 grades D1, D2 and D3?

D1 is the free tolerance, applied to every dimension without its own tolerance. D2 applies to toleranced dimensions and is our standard grade. D3 is the tightest and applies only to dimensions agreed with the foundry, because it needs extra process steps and tooling adjustment. Aluminium and magnesium castings use the matching grades A1 to A3.

Are tolerance table values plus or minus, or the total band?

VDG P690 and ISO 8062-3 list total tolerances, the full width of the band. Placed evenly around the nominal size, half goes each way, so 0.62 mm in total means ±0.31 mm. The band can be set off-centre by agreement, for example on a face that will be machined.

What is ISO 8062-3 and what does DCTG mean?

ISO 8062-3, revised in 2023, is the international standard for general dimensional and geometrical tolerances and machining allowances on castings. DCTG, dimensional casting tolerance grade, runs from 1, the tightest, to 16, the loosest, and the tolerance of each grade grows with the nominal size.

Which ISO 8062-3 grades does each casting process hold?

At Trushape, investment casting and rapid manufacturing hold about DCTG 5 to 7 on typical dimensions, through VDG P690. Gravity die casting holds DCTG 7 to 9, shell molding DCTG 8 to 12, and lost foam and no-bake sand casting DCTG 11 to 14. The grade of a given feature depends on its size, the alloy and the shape of the part.

How does part size affect casting tolerance?

Tolerance grows with size, because metal contraction, mould movement and temperature differences act over a longer length. At VDG P690 grade D2, a dimension up to 6 mm allows 0.24 mm in total, ±0.12 mm, while a 250 to 315 mm dimension allows 2.2 mm, ±1.1 mm.

What machining allowance should a casting have?

ISO 8062-3 sets the required machining allowance per machined surface in grades A to K, read from the largest overall dimension of the casting rather than the feature. Investment castings typically take grade E, for example 1.1 mm per surface on a casting of 100 to 160 mm.

Can you hold tighter tolerances than the casting grade?

Yes. Bores, seal faces, threads and other critical features are machined on our eight CNC machines, including two 4-axis Makino VMCs, to the tolerance on your drawing. Casting close to size keeps the machining stock small, and D3 can be agreed for as-cast features that cannot be machined.

How do you measure and report dimensions?

Critical dimensions are measured on a Zeiss CMM and a Keyence vision measuring machine against your drawing and datums, starting with a first article inspection before series production and continuing with in-process checks. Dimensional reports ship with the parts, together with EN 10204 3.1 material certificates.

Do you work to ASME Y14.5 and ISO GD&T drawings?

Yes. We work to drawings in inches or millimetres, with GD&T to ASME Y14.5 or ISO 1101 and datums to ISO 5459. Datum targets are agreed before tooling, following VDG P690: three points on the primary datum, two on the secondary and one on the tertiary, so casting, machining and inspection all measure from the same places.

Does rapid manufacturing hold the same tolerances as investment casting?

Rapid castings from 3D-printed patterns run through the same investment casting line and typically hold the same VDG P690 grades. Printed patterns vary more than moulded wax, so VDG P690 asks for the tolerances of rapid prototype castings to be agreed case by case, and we confirm them against your drawing before we cast.

Do you supply precision castings to the USA, Canada and Europe?

Yes. Trushape exports castings to Germany, the UK, Belgium, Denmark, Spain and Italy and serves buyers across North America and Europe, including the United States, Canada and Mexico. Parts ship with English dimensional reports and certificates, by sea or air freight, with delivery terms agreed per order.

Explore related capabilities

Ideas shaped, quality delivered

Every drawing names numbers. Trushape casts to the grade each process can hold, machines what needs more and measures it against your datums, for engineers and buyers across North America and Europe.