Dimensions Guide
ESR-1078 
|
 Most Widely Accepted and Trusted  Page 6 of 8 
TABLE 2—REFERENCE WITHDRAWAL DESIGN VALUES (W)
1,2,3
[Reference withdrawal design values (W) are in pounds per inch of thread penetration into side grain of main member] 
FASTENER 
THREAD LENGTH, 
L
4 
(inches) 
W (lbf./in.) FOR SPECIFIC GRAVITIES OF: 
0.57 
0.55 
0.5 
0.46 
0.43 
0.42 
OlyLog/ 
TimberLOK 
1.25 or 2.0 
270 
260 
220 
200 
180 
170 
HeadLOK 
2.0 
290 
270 
230 
200 
180 
170 
LedgerLOK/ 
LogHog 
2.0 or 3.0 
330 
310 
270 
240 
220 
210 
TrussLOK 
1
1
/
2
— 
— 
180 
— 
— 
— 
TrussLOK-Z 
1
1
/
4
290 
270 
220 
180 
160 
150 
ThruLOK
(5)
NA
(6)
1140
(6)
1060
(6)
900
(6)
780
(6)
700
(6)
680
(6)
For SI: 1 inch = 25.4 mm, 1 lbf/in = 175 N/m. 
1
Tabulated reference withdrawal design values, W, apply to fasteners driven into the side grain of the main member, such that the screws are oriented 
perpendicular to the grain and loaded in direct withdrawal. 
2
Reference withdrawal design values must be multiplied by all applicable adjustment factors, in accordance with Section 4.1. 
3
Reference withdrawal design values are to be multiplied by the length of thread penetration into the main member, but must not exceed the head pull-
through design values given in Table 3. Threaded length includes the tapered tip. 
4
See Tables 1A through 1F for thread lengths corresponding to specific fastener model numbers. 
5
The ThruLOK must be used with the ThruLOK washer and nut (supplied with the fastener). The nut must be installed such that it is snug against the 
main member, and at least 
1
/
2
 inch of the threaded portion of the shank (not including the tip) is within the nut. 
6
Tabulated withdrawal values for the ThruLOK are based on the head pull-through design values given in Table 3, as these values will govern designs 
in which the screw is subject to axial tension, where the ThruLOK is properly installed with the ThruLOK washer and nut (see footnote 5 above). 
TABLE 3—REFERENCE HEAD PULL-THROUGH DESIGN VALUES (P)
1,2
FASTENER 
MINIMUM SIDE 
MEMBER 
THICKNESS
(inches) 
P (lbf) FOR SPECIFIC GRAVITIES OF: 
0.57 
0.55 
0.5 
0.46 
0.43 
0.42 
OlyLog/ 
TimberLOK 
1.5 
220 
200 
160 
130 
110 
110 
HeadLOK 
1.5 
630 
600 
520 
460 
410 
400 
LedgerLOK/ 
LogHog 
1.5 
320 
290 
240 
200 
180 
170 
TrussLOK 
1.5 
— 
— 
260 
— 
— 
— 
TrussLOK-Z 
1.5 
370 
330 
250 
200 
170 
160 
ThruLOK
 (3)
1.5 
1140
(3)
1060
(3)
900
(3)
780
(3)
700
(3)
680
(3)
For SI: 1 inch = 25.4 mm, 1 pound = 4.448 kPa. 
1
Reference head pull-through design values, P, must be multiplied by all applicable adjustment factors, in accordance with Section 4.1. 
2
Design values apply to connections with minimum side member thicknesses, t
s
, as given above. 
3
The ThruLOK must be used with the ThruLOK washer and nut (supplied with the fastener). The nut must be installed such that it is snug against the 
main member, and at least 
1
/
2
 inch of the threaded portion of the shank (not including the tip) is within the nut. 










