JIS B 1186 Standard

High strength hexagon bolts for friction grip joints

JIS B 1186 Heavy Hex Bolts

Dimensions of JIS B 1186 Heavy Hex Bolts

Designation of screw threads d1 H B D D1 r K a-b h s
Basic dimension Tolerance Basic dimension Tolerance Basic dimension Tolerance In-formative Min. In-formative Max. Basic dimension Tolerance
M12 12 +0.7 8 ±0.8 22 0 20 20 0.8 to 1.6 2 0.7 0.4 to 0.8 25 +5
M16 16 -0.2 10 27 -0.8 25 25 1.2 to 2.0 0.8 30 0
M20 20 +0.8 13 ±0.9 32 0 30 29 2.5 0.9 35 +6
M22 22 -0.4 14 36 -1 34 33 1.1 40 0
M24 24 15 41 39 38 1.6 to 2.4 3 1.2 45
M27 27 17 46 44 43 1.3 50
M30 30 19 ±1.0 50 48 47 2.0 to 2.8 3.5 1.5 55

Dimensions of JIS B 1186 Heavy Hex Bolts

Designation of screw threads i
Basic dimension
30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 190 200 210 220
M12 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M16 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M20 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M22 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M24 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M27 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
M30 ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯
Tolerance on l ±1.0 ±1.4 ±1.8

The position for measurement of d₁ shall be l0~ d₁/4.
The length x of incomplete thread portion shall be about two threads and that of full threaded about thre threads.
The end portion of screw threads shall be chamfered irrespective of the end shape.
The dimensions l marked with o indicate the preferable lengths l.
The dimensions l and s other than those given in the table, if particularly required, may be used upon the agreement between the purchaser and the manufacturer, provided that s shall not be shorter than the dimensions in the table.
The dimension d1, may be approximately the same as the pitch diameter of screw thread upon the agreement between the purchaser and the manufacturer.
In this case, the radius under head r may be made as follows.
Designation of screw threads M12 M16 M20 M22 M24 M27 M30
r 1.2 to 2.4 2.0 to 3.3 2.5 to 3.8