NXF UNS S31603 316/0Cr17Ni12Mo2/1.4401 Class150-3000 316 Stainless Steel Casting Threaded Straight or Reducing Haxagonal Nipple

1.Raw‑material InspectionWe adopt qualified 316L stainless‑steel ingots. Each batch receives spectrum component detection to verify low‑carbon molybdenum‑alloy composition. Unqualified raw materials will be eliminated before production to guarantee corrosion‑resistant performance of finished hexagonal nipples.

2.Wax Mold MakingPrecision injection moulding produces complete wax patterns for straight and reducing hexagonal nipples. Strict size calibration ensures the hexagon outline, male‑thread allowance and inner‑bore dimension conform to drawing requirements.

3.Shell‑Mould PreparationDip wax patterns in multiple‑layer refractory slurry, carry out sand‑coating and natural drying. The thick‑formed ceramic shell obtains high hardness, which avoids deformation during high‑temperature pouring.

4.Dewaxing and High‑Temperature RoastingSteam heating melts and drains out internal wax. The mould shell is baked under high heat to clear residual wax waste and strengthen the shell structure for casting.

5.Molten‑metal PouringMelt the 316L stainless‑steel material at high temperature. Pour liquid alloy into pre‑heated ceramic shells under vacuum casting technology for dense, pore‑free one‑piece casting blanks.

6.Shell Breaking and Blasting TreatmentBreak off the refractory shell after cooling. Perform sand‑blasting on casting blanks to remove surface oxide scale, burrs and sticky sand for a smooth workpiece surface.

7.CNC Machining & Thread FabricationMachine hexagonal outer flats, end faces and inner holes. Precision‑tap standard BSP or NPT male threads for both equal‑diameter straight and reducing‑type nipples, with thread tolerance strictly controlled.

8.Defect Inspection and Pressure‑Resistant TestCarry out visual inspection, size checking and flaw detection. Random‑sample leakage‑testing guarantees no thread seepage under rated working pressure.

9.Surface Finishing and PackingCarry out pickling‑passivation anti‑corrosion treatment. Sort finished‑product models, then pack qualified hexagonal nipples into anti‑rust packages for shipment.