Oil Hardening Tool Steel for Car Mould Making

Oil Hardening Tool Steel for Auto Car Trim Mould Making

The oil hardening tool steels are probably used in plastics auto car door mould manufacture as extensively as are all of the other mold steels together. This includes carburizing steels, hobbing steels, water and air hardening steels.

Next to the air hardening steels, those which may be hardened by quenching in oil have the lowest distortion characteristics of all of the tool steels. The distortion of oil hardening tool steels upon heat treatment is less than the tolerance limits for some plastics mold applications, and this advantage, coupled with favorable machinability, accounts principally for their wide use. When the accuracy limits for finished mold parts are closer than the expected distortion, it is often possible to make allowances for distortion, and thus still hold the required accuracy with an oil hardening tool steel.

Hardness control, from extremely hard to fairly soft surfaces, is possible when oil hardening tool steels are used. Brightly polished surfaces, having good abrasion and crushing resistance, may be produced on car bumper mould cavity parts made of these steels. Guide pins, bushings, cams, cutting tools, and other mold parts which require high strength and hardness are usually made of oil hardening tool steels for best all around results.

The analyses of ten typical oil hardening steels which are used extensively for plastics molds are tabulated in Fig. below