Manufacturer of Industrial Hardware Supply Since 1973.
To fasten tighter, there's serration beneath the head. It is usually put on office chair, steel table leg and etc.
1. M6-1.0; length 10mm ~ 80mm.
2. M8-1.25; length 12mm ~ 80mm.
3. M10-1.5; length 16mm ~ 100mm.
4. Inch size is also available.