Machines and Equipment

Steel cutting machines      Lathe Turning Machines        Drilling Machines    Milling Machines

Grinding Machines            Barrel Deep-Hole Boring and Honing Machines      Straightening Machines

CNC Machining Facilities, including mills and lathes       Welding Machines (PTA, etc.)

Polishing Machines           Nitriding Furnaces            Barrel Centrifugal Casting Equipment

Manufacturing Expertise

Most screws are manufactured from high quality 38CrMoAlA( SCM645 in JIS ) steel which is a chromium-aluminium-molybdenum nitriding steel. Nitriding is a heat treating process that diffuses nitrogen into the surface of the screw, to produce a hard surface on the component. Depending on the size of the screw either a gas or plasma nitride process is used to give an even depth of hardness across the screw profile. After Nitriding, a minimum surface hardness of 950 Vickers (VPN), equivalent to 68 Rockwell is achieved with a hardness a depth of between 0.4 – 0.6 mm. Nitrided screws provide a good general purpose component that can be refurbished to standard at a later date.

For more demanding high wear or corrosion applications, in addition to the normal nitriding process, screws can be supplied with additional surface treatments including hard facing on the flight lands or coated to provide the optimum resistance. Yashi Screw offers a number of hard facings applied through Plasma Transferred Arc (PTA),  Tungsten Inert Gas (TIG) welding processes and HVOF thermal spray coating..

Weld applied Hard facing grades include:

Nickel-Base Hard-Surfacing Alloy with Chromium Boride(CrB2)

Cobalt- Base Hard-surfacing Alloy

Further coatings can be provided including:

HCP (Hard Chrome Plating)

Fe-based Alloy Inlays

Stainless Steel inlays

Tungsten Carbide

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