Before Requesting the Manufacture of Special Screws – Start by Searching in Japan
If you feel that special screws are necessary, why not first look into “special screws made in Japan” before proceeding to custom manufacturing?
While we may not know the specific conditions of screw manufacturing in your country, it’s common—especially during the final stages of design or prototype development—to encounter a situation where standard, commercially available screws just won’t work.
For engineers in countries where screw production must rely on overseas sources, outsourcing something as “simple” as a screw can be a troublesome task.
In Japan, however, there are many screws available that can solve these kinds of problems.
These are not general-purpose screws, but a wide variety of special screws are available from stock.
1. For example, stainless steels like type 304, 18-8 stainless, and A2 stainless cannot be strengthened through heat treatment.
With cold forming, the highest strength typically achievable is A2-70, but in Japan, high-strength stainless bolts like A2-100 are available in stock.
2. High-strength bolts of grade 12.9 cannot usually be electroplated due to the risk of hydrogen embrittlement.
However, in Japan, special plating processes are available that prevent hydrogen embrittlement, and such bolts can be obtained from stock.
3. Delayed fracture is a known risk with high-strength bolts.
While 12.9 is the highest grade specified under ISO, DIN, and JIS standards, Japan offers even higher-strength bolts designed to reduce the risk of delayed fracture—some of which are available in stock.
Even grade 14.9 bolts can be sourced from inventory.
For example, if you’ve designed your product around an M12 12.9 bolt but find that the strength is still insufficient—and yet you’re constrained to use only M12 screws—these higher-strength options can provide a valuable solution.
【Writer】Tak Saima/CEO, Technical Sales