8Mark bolt(Small(Full thread(Fine Steel Trivalent stain coat(Silver) 16X25(1.5 Pitch 2.0

This product is a screw equivalent to strength class 8T.
The head is marked with either "7" or "8".
It has a regular hexagonal head and is tightened using a wrench or spanner.
It can be tightened more securely than slotted or cross recessed screws.
Full thread = a bolt that is threaded from the hex head all the way to the tip.
Partial thread (medium bolt) = a bolt that is threaded from the tip partway up the shank.
Partial thread length calculation method (approximate guide):
L = up to 129     nominal thread diameter × 2 + 6
L = 130 to 219   nominal thread diameter × 2 + 12
L = 220 and over   nominal thread diameter × 2 + 25
Example: For an M10×250 partial thread bolt, since L (length) is 220 or greater, the threaded length = 10×2+25 = 45mm.
Thread Pitch & Hex Width Across Flats Reference Chart　Hex Bolt Encyclopedia

• 8 Mark bolt Small Full thread Fine pitch
• Nominal thread diameter (d) M16
• Length under head (ℓ) 25.0
• Pitch fine (p) 1.5
• Head height (k) Nominal 10 Tolerance ±0.3
• Width across flats (s) Nominal 22 Tolerance 0,-0.8
• Width across corners (e) Approximately 25.4