Casting Tolerances


Functional Dimensions

 

Inches

Millimetres

Dimension

Tolerance

Dimension

Tolerance

Up to 0.500

±.004"

Up to 12.0

± 0.10mm

Up to 0.500

±.006"

12.0+ to 25.0

± 0.15mm

1.000+ to 1.500

±.008"

25.0+ to 37.0

± 0.20mm

1.500+ to 2.000

±.010"

37.0+ to 50.0

± 0.25mm

2.000 + to 2.500

±.012"

50.0+ to 62.0

± 0.30mm

2.500+ to 3.500

±.015"

62.0+ to 87.0

± 0.35mm

3.500+ to 5.000

±.018"

87.0+ to 125.0

± 0.45mm

5.000+ to 7.500

±.021"

125.0+ to187.0

± 0.53mm

7.500+ to 10.000

±.024"

187.0+ to 250.0

± 0.60mm

10.000+ to 12.500

±.027"

250.0+ to 312.0

± 0.68mm

12.500+ to 15.000

±.030"

312.0+ to 375.0

± 0.75mm

Each additional inch add ± .001"

Each additional 25mm add ± .025mm

Non-Functional Dimensions

Where design parameters permit the above tolerances should be increased by 50%

Wall Thickness Tolerance

Special tolerances apply to wall thicknesses. The normal tolerance to be allowed is ± .008" (±0.20mm)

Large plain wall sections, above 75sq inches (500sq cm), should incorporate a tolerance of ±0.012" (±0.3mm)

Straightness/Flatness Tolerance

±0.004" (±0.10mm) per inch (per 25mm) excluding localised wax pattern depressions.

Angular Tolerance
±1/2°

Surface Finish
Typical surface finish - 80/100 microinches (2.0/2.5 micrometres). A finer surface finish is generally attainable when specifically requested.

Geometric Tolerances
Are dependant on the casting configuration and/or alloy specification, and would be discussed on an individual basis at the quotation stage.