Description

Technical Parameters

Why Lost Wax for Stainless Steel

Factor	Lost Wax Casting	Sand Casting	Machining from Bar
Surface finish	Ra 3.2–6.3μm as cast	Rougher	Machined finish
Complex shapes	Thin walls, internal cavities	Limited fine detail	Costly to cut
Material waste	Low	Low to moderate	High; stainless bar is expensive
Machining allowance	Small	Larger	Not applicable
Best fit	Small to mid-size complex parts	Large, simple bodies	Prototypes, very low volume

Grade Selection Guide

Your Environment	Recommended Grade	Reason
Indoor, food contact, mild moisture	304	Good general corrosion resistance at lower cost
Coastal, marine, chloride exposure	316	Molybdenum improves resistance to pitting
Welded assemblies	316L	Low carbon reduces weld-related sensitization
Pump and valve bodies, corrosive fluids	CF8M	Cast equivalent of 316 for pressure-containing parts

Corrosion-Focused Process Controls

Solution annealing: dissolves carbides so chromium stays available to resist corrosion
Pickling: removes heat-treatment scale and surface oxide
Passivation: rebuilds the chromium oxide film and clears iron contamination left by machining
Electropolishing (optional): smoother, cleaner surface for sanitary or high-purity service
Clean handling: stainless-only tooling and racks in finishing, so carbon steel particles are not transferred to the surface

Specifications

Item	Detail
Alloys	304, 316, 316L, CF8M
Casting tolerance	±0.2mm
Machined tolerance	±0.02–0.05mm on critical features
Secondary operations	CNC turning, milling, drilling, tapping
Finishes	As cast, shot blasted, polished, electropolished
Input	STEP, IGS, PDF/2D drawing, or physical sample

Manufacturing Process

Wax pattern: precision wax tooling built to your drawing
Ceramic shell: pattern shelled for dimensional stability
Dewax and casting: shell fired, then poured in the specified stainless grade
Heat treatment: solution treatment or annealing to restore corrosion resistance
CNC machining: bores, flange faces, and threads brought into tolerance
Surface finishing: pickling, passivation, or polishing
Inspection and packaging: final check, cleaning, export packing

Typical Parts

Stainless-Specific Inspection

Check	Purpose
Spectrometer / PMI	Confirms chromium, nickel, and molybdenum content match the grade
CMM measurement	Verifies dimensions against your drawing
Dye penetrant (PT)	Detects surface cracks and porosity
Pressure test	Confirms leak-tightness of valve and pump bodies
Salt spray or pickling test	Corrosion verification, on request

Material certificate and inspection report are available with each shipment.

FAQ

Q1:	Is cast stainless steel magnetic?
A1:	Fully austenitic 304 and 316 are essentially non-magnetic, but cast grades such as CF8M contain some ferrite and may show slight magnetism. This is normal and does not indicate a defect.
Q2:	Does machining reduce corrosion resistance?
A2:	It can, because tooling may leave iron particles on the surface. Passivation after machining removes them and restores the protective film.
Q3:	Should I choose 316L or CF8M?
A3:	316L suits welded fabrications. CF8M is the usual choice for cast pressure-containing bodies such as pump and valve housings.

Lost Wax Casting Stainless Steel