ステンレス 六角ボルト - Stainless Rokaku (Hexagon) Bolt
 
Stainless steel bolts with standard head size and thread pitch. Be careful for M8 and above, your bike may require a fine thread bolt sold in a different page. 
 
Hexagonal head bolts commonly used by restorer but not found on orginal bikes where zinc plating was the standard. Shorter bolts have a full thread while bolts longer than 40 millimeters are not fully threaded except for M3 bolts which are all fully threaded.
 
There are no markings on the bolts heads. They looks great and can be polished to be almost like chrome.
Stainless steel has excellent corrosion and heat resistance. 
 
On the downside these bolts are expensive and I do not recommend stainless because of potential galling when set with aluminium parts like our engines. Always use a lubricant or interface when mounting.
 
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