To provide a method for producing a spring washer-fitted high tensile strength bolt by various steel kinds, where the use of raw material not quenched as the material for a bolt is facilitated, and the production cost of the spring washer-assembled bolt is reduced.
The spring washer is produced by an SNCM based steel member containing 0.35 to 0.50% C, 0.30 to 0.60% Ni, 0.80 to 1.10% Cr, 0.80 to 1.10% Mo and 0.040 to 0.10% V. By precipitation hardening of Mo and V, its hardness is not so lowered even when being tempered in the temperature range of 500 to 600°C, thus, even in the case a bolt is made of various steel kinds and tempering temperatures are greatly different, its required hardness (spring properties) can be secured by tempering together with the bolt. As a result, in producing the bolts of various kinds, time and labor of preparing spring washers of many kinds of materials can be eliminated while making service life of a die longer.
MORIKAWA TSUTOMU
OSAKA SEIKO KK
| JP2002020839A | 2002-01-23 | |||
| JP2004238727A | 2004-08-26 |
Tadashi Higashino
Hiroyuki Nishi
Ryuichi Watanabe
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