bivite parallela e cilindro

Screw:Cutting stell—Machining—Drill hole—Quenching&Tempering

—Machining outside diameter

—Milling screw arris—

Heat treament—Milling screw arris accurately—polishing—

grinding outside diameter—

milling spline—Nitriding—

 polishing again—Inspecting

—Package

Barrel:Cutting stell

—Machining—Drilling hole—Rough machining

—Hardening&Tempering

—Machining again

—Grinding inner hole

—finish machining

—milling feeding hole—

Nitriding—grinding inner hole again—polishing

—package

Hrad Plastic polystyrene

PS.ABS.SAN.EPN                          

Soft Plastic polystyrene

LDPE.HDPE.UHMPE.EVA.

Polypropylene

PP

PVC

UPVC

Polyacrylic resin

PMMA

Polyacetal class

POM

Nylon class

PA6.PA12.PA66.PAST

polyester class

PET PBT UP

screw barrel are wrapped in a layer of plasticfilm

then will be fixed in a strong wooden case