To provide a valve guide having excellent wear and abrasion resistance and machining working properties at a low price by providing an enlarged diameter stepped part having required length on the inner periphery of both longitudinal end parts in a cylindrical guide body, and fittedly attaching an annular member formed of excellent wear and abrasion resistant material in both the enlarged diameter stepped parts.
A valve guide 1 is composed of a guide body 2 having expanded diameter stepped parts 2a severally formed on the inner peripheries of vertical end parts and an annular member 3 fittedly attached in both the expanded diameter stepped parts, and the length of the expanded diameter stepped part 2a is set up to be about 1/3 of the total length of the valve guide 1 or less than the above total length. The guide body 2 is formed of free-cutting steel having added machinability improving element of a middle carbon steel, and on the other hand, the annular member 3 is formed of excellent wear and abrasion resistant material such as high-speed steel. Thus when the guide body 2 is formed of material having excellent machinability, and only both its end parts are formed of material having excellent wear and abrasion resistance, machinability becomes excellent, and the life of a tool can be elongated and the manufacturing cost can be reduced.
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