Hex bolt(Full thread(otherFine Steel Zinc plated(Silver) 12X40(BT(Full thread(B19(P1.5 Pitch 1.75

Generally, a bolt refers to a screw used together with a nut. Among these, the representative hex bolt features 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 in which the entire length below the head is threaded. (Generally for lengths of 30mm or less)
●Partial thread (standard bolt) = A bolt that is only 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 = 130–219　　　 Nominal thread diameter × 2 + 12
L = 220 and above　　　 Nominal thread diameter × 2 + 25
Example: For an M10×250 partial thread bolt, since L (length) is 220 or greater, the thread length is 10×2+25 = 45mm.
Thread Pitch and Hex Width Across Flats Reference Chart　Hex Bolt Encyclopedia

• Hex bolt Full thread Other fine pitch
• Nominal diameter (d) M12
• Pitch (p) 1.5
• Length under head (ℓ) 40.0
• Width across corners (e) Approx. 21.9
• Width across flats (s) Nominal 19.0 Tolerance 0,-0.35
• Head height (k) Nominal 8.0 Tolerance ±0.2