Investment Casting Tolerances VDG P690

Modulus Metal Türkiye Turkey Investment Casting Lost Wax Precision Casting Foundry Supplier Company in Turkey Turkiye

Material-group	Materials	Accuracy grade
D	alloys based on iron, nickel, cobalt and copper	D1 to D3
A	alloys based on aluminium and magnesium	A1 to A3
T	alloys based on titanium	T1 to T3

MATERIAL GROUP D – LINEAR DIMENSIONAL CASTING TOLERANCES (IN MM)
Nominal Size	D₁ tolerance	D₂ tolerance	D₃ tolerance
up to 6	±0.15	±0.12	±0.10
over 6 up to 10	±0.18	±0.14	±0.11
over 10 up to 18	±0.22	±0.17	±0.14
over 18 up to 30	±0.26	±0.20	±0.17
over 30 up to 50	±0.40	±0.31	±0.25
over 50 up to 80	±0.45	±0.37	±0.30
over 80 up to 120	±0.55	±0.44	±0.35
over 120 up to 180	±0.80	±0.65	±0.50
over 180 up to 250	±1.20	±0.95	±0.75
over 250 up to 315	±1.30	±1.10	±0.80
over 315 up to 400	±1.80	±1.40	–

MATERIAL GROUP A – LINEAR DIMENSIONAL CASTING TOLERANCES (IN MM)
Nominal Size	A₁ tolerance	A₂ tolerance	A₃ tolerance
up to 6	±0.15	±0.12	±0.1
over 6 up to 10	±0.18	±0.14	±0.11
over 10 up to 18	±0.22	±0.17	±0.14
over 18 up to 30	±0.26	±0.2	±0.17
over 30 up to 50	±0.4	±0.31	±0.25
over 50 up to 80	±0.45	±0.37	±0.3
over 80 up to 120	±0.55	±0.44	±0.35
over 120 up to 180	±0.8	±0.65	±0.5
over 180 up to 250	±0.95	±0.75	±0.6
over 250 up to 315	±1.3	±1.1	±0.8
over 315 up to 400	±1.4	±1.2	±0.85
over 400 up to 500	±1.6	±1.3	±0.95
over 500 up to 630	±2.2	±1.7	–
over 630 up to 800	±2.5	±2	–
over 800 up to 1000	±2.8	±2.3	–
over 1000 up to 1250	±3.3	–	–

MATERIAL GROUP T – LINEAR DIMENSIONAL CASTING TOLERANCES (IN MM)
Nominal Size	T1 tolerance	T2 tolerance	T3 tolerance
up to 6	±0.25	±0.2	±0.2
over 6 up to 10	±0.3	±0.2	±0.2
over 10 up to 18	±0.35	±0.25	±0.22
over 18 up to 30	±0.4	±0.35	±0.26
over 30 up to 50	±0.5	±0.4	±0.31
over 50 up to 80	±0.75	±0.6	±0.45
over 80 up to 120	±0.85	±0.7	±0.55
over 120 up to 180	±1	±0.8	±0.65
over 180 up to 250	±1.2	±0.95	±0.75
over 250 up to 315	±1.6	±1.3	–
over 315 up to 400	±1.8	±1.4	–
over 400 up to 500	±2	±1.6	–
over 500 up to 630	±2.7	±2.2	–
over 630 up to 800	±3.1	±2.5	–
over 800 up to 1000	±3.6	–	–
over 1000 up to 1250	–	–	–

ANGLE TOLERANCES FOR MATERIAL GROUPS D, A AND T
Nominal dimension range¹⁾	Accuracy³⁾
	1		2		3
	Allowed deviation of direction
	Angular minute	mm per 100 mm	Angular minute	mm per 100 mm	Angular minute	mm per 100 mm
up to 30 mm	30²⁾	0.87	30²⁾	0.87	20²⁾	0.58
over 30 up to 100 mm	30²⁾	0.87	20²⁾	0.58	15²⁾	0.44
over 100 upto 200 mm	30²⁾	0.87	15²⁾	0.44	10²⁾	0.29
over 200 mm	30²⁾	0.58	15²⁾	0.44	10²⁾	0.29

1) The nominal-dimension range is determined by the length of the shorter side.

2) The angle may deviate in both directions Tolerances of angle differing from those given in table 3 must be agreed between supplier and user, and entered in the drawing in accordance with DIN ISO 1101.

3) For investment castings based on Titanium alloys accuracy grade 1 has to be applied

RADIUS OF CURVATURE The tolerances stated apply for the material groups D, A and T.
Nominal dimension range	Accuracy¹⁾
	1	2	3
	Radius of curvature (mm)
up to 5 mm	± 0,30	± 0,20	± 0,15
over 5 up to 10 mm	± 0,45	± 0,35	± 0,25
over 10 up to 120 mm	± 0,70	± 0,50	± 0,40
over 120 mm	use linear tables

1) For investment castings based on Titanium alloys accuracy grade 1 is generally valid.

DIMENSIONAL TOLERANCE FOR WALL THICKNESSES

The tolerances of wall thickness are dependent on:

The size of the ceramic shell mould
Its uninterrupted surface
Its possible thermal deformation
Its possible thermal deformation

Tolerances for wall thickness are therefore not dependent on the degree of accuracy. They are limit ed (or reduced) by thicker edge areas, openings (holes, webs) ribs, etc., all of which relieve stress on the wall thickness.

Investment Casting Wall Thickness Example Figure

Case A: The surface formed by dimensions a and b is not interrupted. Dimension b is smaller than dimension a. Dimension b determines the tolerance of wall thickness.

Case B: The area formed by dimensions a and b is interrupted by a hole in the centre. The uninterrupted surface is therefore formed by dimensions b and c. Dimension c is smaller than dimension b. The wall-thickness tolerance is therefore determined by dimension c.

For the applicable tolerance range, refer to the table below. This contains the lengths of the smallest side of a surface (with reference to material group) on which the wall-thickness tolerance depends. The tolerances apply for unmachined surfaces only.

WALL THICKNESS TOLERANCES
Smallest lateral length of a surface (Example Figure Above)	Material group D [mm]	Material group A [mm]	Material group T [mm]
up to 50 mm	± 0.25	± 0.25	± 0.30
over 50 up to 100 mm	± 0.30	± 0.30	± 0.40
over 100 up to 180 mm	± 0.40	± 0.40	± 0.50
over 180 up to 315 mm	± 0.50	± 0.50	± 0.60
up to 315 mm	± 0.60	± 0.60	± 0.70

SURFACE QUALITY

For cast surfaces, R_a (CLA) shall be applied in accordance with table below.

SURFACE ROUGHNESS
Surface standards	Material group D		Material group A		Material group T
Surface standards	CLA [µinch]	R_a (µm)	CLA [µinch)	R_a [µm]	CLA (µinch)	R_a [µm)
N 7	63	1.6
N 8	125	3.2	125	3.2
N 9	250	6.3	250	6.3	250	6.3

Zone N7, N8, and special surface treatment must be agreed separately and entered in the drawing in accordance with DIN ISO 1302. Unless otherwise agreed, N9 in the shot-blasted state is the standard delivery condition.

TOLERANCES FOR HOLES, BLIND HOLES AND CHANNELS (IN MM)
Diameter (d)	Max. length or depth respectively
in mm	Through (I)	Blind (t)
2 to 4	≈ 1 x d	≈ 0.6 x d
over 4 up to 6	≈ 2 x d	≈ 1.0 x d
over 6 up to 10	≈ 3 x d	≈ 1.6 x d
over 10	≈ 4 x d	≈ 2.0 x d

TOLERANCES FOR SLOTS AND GROOVES (IN MM)
Width (w)	Greatest depth
in mm	Open (I)	Closed (t)
2 up to 4	≈ 1 x w	≈ 1.0 x w
over 4 up to 6	≈ 2 x w	≈ 1.0 x w
over 6 up to 10	≈ 3 x w	≈ 1.6 x w
over 10	≈ 4 x w	≈ 2.0 x w

Design for Investment Casting Process

Investment Casting