Improve Quality By Design

The best test of any manufacturing process is that you get the same quality after the thousandth part as you got on the first. That your design holds its dimensions and tolerances to multiple decimal points through every unit produced.

Other manufacturers call it exceptional repeatability. At Super Quali Cast, we call it business as usual.

Investment casting is already capable of excellent repeatability, but with early involvement and input by our technical staff, we take it even further.

Using our expert knowledge and world-leading technology, we can quickly identify and virtually eliminate sources of tolerance variation. And we don’t restrict ourselves to any single factor. We’ll create value right across part design, tooling, position, and production.

All you need to remember? Get Super Quali Cast involved in design early.

Make precision possible. Every time.

Tolerance & Dimensions


As-cast finishes will vary with alloy specified but generally fall within the range quoted. For a ground finish an allowance of 0.010 in. (0.25mm) should be made.

Metal C.I.A. value
As-cast Machined
Stainless Steels 90-126 60-125
Cobalt Chrome Alloys 80-100 50-100
Carbon Steels 90-125 60-125


Shape and alloy selected will influence accuracies achieved but values given are normally accepted through out the investment casting industry.

Dimension Tolerance
Upto 25 mm ±0.25mm
Above 25 mm ±0.25mm/25mm

Closer tolerance may be held on selected dimensions following design evaluation.


There are practical limits to straightness which can be achieved but mechanical straightning can reduce variations.

Casting Length As-cost Corrected
25 mm ±0.50 mm ±0.25 mm
50-100 mm ±0.75 mm ±0.50 mm
100-150 mm ±1.00 mm ±0.50 mm
150 mm ±1.50 mm ±0.62 mm


Flatness is also affected by dimensions of casting. Addition of ribs will minimize bowing, twisting and distortion and mechanical straightning will reduce variations where necessary.

Casting Length As-cost Corrected
25 mm ±0.20 mm ±0.10 mm
50 mm ±0.37 mm ±0.15 mm
75 mm ±0.50 mm ±0.20 mm
100 mm ±0.62 mm ±0.25mm


Depth (D) and Diameter(d) of hole must allow for adequate penetration of investment material. Values given show usual limits for cast holes but pre-formed ceramic cores allow this restrictions tobe exceeded, although usually at increased cost.

Through holes
Diameter (d) mm Maximum Depth (D) mm
3.17-6.35 D upto 1.5 d
6.35-12.70 D upto 3.0 d
12.70  D upto 5.0 d
Blind Holes
Diameter (d) mm Maximum Depth (D) mm
4.76-12.70 D upto 1.5d
12.70  D upto 2.0 d


The larger the outside diameter becomes, the closer to concentric an inside diameter can be cast.

Mechanical correction can normally be made where wall thickness is thin enough to allow plastic deformation.

O.D.(mm) I.D. (mm) Eccentricity (mm)
As-cast Corrected
18.75 6.25 ±0.100 ±0.100
25.00  12.50  ±0.125 ±0.125
37.50  18.45 ±0.200 ±0.200
50.00  25.00  ±0.250  ±0.200


For solid bars roundness is affected by solidification stresses and tolerance required increases nearly in proportion to diameter, inline with usual 'Lost Wax' tolerances.

Values shown are for as-cost roundness on inside and outside diameters of tubes of varying sizes. Wall thickness is important and tighten tolerance can be obtained by mechanical correction if desired.

O.D. (mm) Tolerance (mm) I.D. (mm) Tolerance (mm)
12.50 ±0.25 upto 6.25 ±0.30
25.00 ±0.50 6.25-12.50 ±0.40
37.50 ±0.60 12.50-25.00 ±0.50
50.00 ±0.75 above 25.00 ±0.50 (per 25 mm)


Wall thickness will depend upon area of casting and alloy selected. The following values are of guide from general experience.

Material Minimun wall thickness obtainable
18/8 stainless steels 1.62 mm
25/12 stainless steels 1.50 mm
Carbon steels 2.25 mm
Cobalt-Chrome alloy 1.12 mm


Parallelism can be maintain by adding fire-bars to minimize distorsions. Values shown are typical tolerances for various gap-widths between parallel sections per inch cost.

Gap (mm) Tolerance(mm) As-cast Corrected
6.25 ±0.075 ±0.075
12.50 ±0.125 ±0.100
18.65 ±0.150 ±0.100
25.00 ±0.175 ±0.125


Angles: Angular tolerance to ±1/2° (Closer by mechanical corrections).

Symbols: Latters, Numbers, etc., can be reproduce in relief or inset.

Serrations, Splines and Gear Teeth may be cast in certain instances subject to prior agreement.