Chang Gu Viet Nam logo CHANG GUViet Nam Co., Ltd
Range of stainless steel pipe fittings

Material grades and tolerances

A reference sheet for engineers specifying a stainless steel casting. Everything here is public standard data — use it to check your drawing before you send it.

Cross reference

Cast grade vs wrought grade

This is where most drawing queries start. A casting cannot be made in a wrought bar grade — the equivalent cast grade has its own designation and slightly different chemistry, because the alloy has to behave in a mould rather than in a rolling mill.

Cast grade (ASTM A351)Wrought equivalent (AISI)DIN / ENJISTypical use
CF8AISI 3041.4308 / GX5CrNi19-10SCS13General corrosion resistance, sanitary and food contact parts
CF8MAISI 3161.4408 / GX5CrNiMo19-11-2SCS14Chloride and acid resistance, valve and pump parts, marine
CF3MAISI 316L1.4409 / GX2CrNiMo19-11-2SCS16ALow-carbon version, for welded assemblies
CA15AISI 4101.4008 / GX12Cr12SCS1Higher strength structural castings

If your drawing quotes a wrought grade such as 316L, tell us in the RFQ — we confirm the cast equivalent with you in writing before quoting, rather than substituting silently.

Tolerances

What the process holds, and what machining holds

Investment casting is a near-net-shape process, not a finishing process. The practical way to read a drawing is to split it into features that can come straight off the shell and features that need a cutter afterwards.

General as-cast toleranceFollows the general investment casting classes in ISO 8062 (CT grades). The class that applies depends on the dimension and on whether it crosses the parting line.
Across the parting lineAlways looser than within one half of the tool. If a dimension is critical, ask us to orient it inside one half at the tooling review stage — that decision is free before the die is cut and expensive afterwards.
Machined featuresHeld to the drawing on our own CNC lines. Threads are checked with go / no-go gauges; sealing faces and locating faces are machined rather than cast.
Machining stockAgreed per feature during drawing review. Too little and a low spot appears after cutting; too much and you pay for metal and cycle time you do not need.

These are process characteristics, not a promise about your part. The quotation states the tolerance we commit to for each critical feature you mark.

Interactive tool

Alloy addition calculator

The working tool our melt shop uses on the furnace platform: enter the spectrometer reading and the bath weight, and it returns the alloy addition needed to bring the heat into spec. It is open for you to use — and it is a fair picture of how we run a melt.

Open the calculator

Surface

Surface finish options

  • As-cast — smoother than sand casting, suitable for non-visible surfaces
  • Blasted — uniform matt finish, the usual starting point
  • Satin — brushed appearance for visible hardware
  • Polished — bright finish for sanitary and foodservice parts

Tell us which surfaces are visible on the finished product. That single line on a drawing changes both the process route and the price.

Grinding and deburring a casting

Have a drawing? Get a casting quote.

Send a 2D drawing or 3D model with material, quantity and market. You get a manufacturability review and a price.

Start an RFQ