ASTM A325 TC BOLTS GRADE 8.8S 10.9S FOR STEEL STRUCTURE

 Features of High Strength T.C. (Tension Control) Bolts

T.C. bolts, improved type of heavy hexagonal structural bolts, were developed

for more simplified bolt fastening and more accurate performance and offer such

excellent characteristics as shown below because no fastening technique of high

level is required :

Installation Procedure

The bolt reacts to the fastening torque and the notched end of the bolt shears off.

The required clamping force is thus given.

1 Controlled clamping force can be ensured.

2 Completion of bolt fastening can be comfirmed by the shear-off

of the notched end of the bolt.

3 Fastening can easily be done by electric wrench.

4 Noiseless installation and no need of wrench adjustment.

5 The bolt does not rotate when fastening.

6 No apprehension of bolts being left unfastened.

Determination of Bolt Length

Classes and Grades

Mechanical Properties

Machined Test Pieces

Grade of bolt according Yield Tensile Elongation Reduction

to mechanical properties strength strength (%) of area

(N/mm2) (N/mm2) (%)

S 10 T 900 min. 1000 ~ 1200 min. 14 min. 40 min.

Full Size Bolts

Tensile load (min.) (KN)

Grade of bolt according

to mechanical properties Nominal size of threads Hardness

M16 M20 M22 M24 M27 M30

S 10 T 157 245 303 353 459 561 HRC 27 ~ 38

Nuts

Grade of nut according Hardness

to mechanical properties Proof load

Min. Max.

F 10 HRB 95 HRC 35

Same as tensile

load (min.) of bolt

Hardness of Washers

Grade of washer according to mechanical properties Hardness

F 35 HRC 35 ~ 45

High Strength T.C. Bolts (JSS II 09 S10T)

4

50 s

Shape and Dimensions

High Strength Tension Control Bolts

Nominal d1 H D r s

size of

threads Basic Tolerance Basic Tolerance Min. Basic Tolerance

(d) dimension dimension dimension

+0.7 +5

M16 16 ~ 10 ±0.8 26 30 ~

-0.2 0

1.2 ~ 2.0

M20 20 13 33 35

M22 22 14 37 40

+0.8 ±0.9 +6

M24 24 ~ 15 41 45 ~

-0.4 1.6 ~ 2.4 0

M27 27 17 47 50

M30 30 19 ±1.0 53 2.0 ~ 2.8 55

Unit: mm

Nominal bolt length (l) Tolerance

30 up to 50 ±1.0

55 up to 120 ±1.4

125 up to 180 ±1.8

d C

B

90°~120°

D1

H

h

50 s

D 30°

50 s

Unit: mm

Heavy Hexagon Nuts

Nominal Outside H B C D D1 h

size of diameter

threads external Basic Tolerance Basic Tolerance Approx. Approx. Min.

(d) thread dimension dimension

0

M16 16 16 ±0.35 27 ~ 31.2 25 25

-0.8

M20 20 20 32 37.0 30 29

0.4

M22 22 22 36 41.6 34 33 ~

0 0.8

M24 24 24 ±0.4 41 ~ 47.3 39 38

-1

M27 27 27 46 53.1 44 43

M30 30 30 50 57.7 48 47

5

Unit: mm

Plain Washers

d D t

Nominal

size of Basic Tolerance Basic Tolerance Basic Tolerance

washers dimension dimension dimension

+0.7

M16 17 ~ 32

0 4.5 ±0.5

M20 21 40 0

~

M22 23 +0.8 44 -1

~

M24 25 0 48 6

M27 28 56 ±0.7

+1.0 0

M30 31 ~ 60 ~ 8

0 -1.2