Withdrawal Resistance of Lag Screws in Wood
Withdrawal Resistance of Lag Screws in Wood
(OP)
Hello,
What effect does "edge distance" have on lag screw withdrawal resistance in wood? I need a source as well, just let me know your source and I'll look it up!
I found in "Standard Handbook of Fastening and Joining" a chart that was reproduced from AF&PA source, wherein a withdrawal strength was related to lag screw diameter and wood specific gravity. Well I know that it also depends on the thread penetration, but I wonder if it matters what the "edge distance" is.
Or maybe it is enough if I specify a minimum "edge distance", such as 4 diameters or 1.5 diameters. For instance, in the same book under lateral loading, if the direction of loading is parallel to the grain the min. edge distance is 1.5 diameters, if the loading is perpendicular to the grain the min. edge distance is 4 diameters.
-= Any Help Is Appreciated =-
Thank you,
"Grunchy" P.E.
What effect does "edge distance" have on lag screw withdrawal resistance in wood? I need a source as well, just let me know your source and I'll look it up!
I found in "Standard Handbook of Fastening and Joining" a chart that was reproduced from AF&PA source, wherein a withdrawal strength was related to lag screw diameter and wood specific gravity. Well I know that it also depends on the thread penetration, but I wonder if it matters what the "edge distance" is.
Or maybe it is enough if I specify a minimum "edge distance", such as 4 diameters or 1.5 diameters. For instance, in the same book under lateral loading, if the direction of loading is parallel to the grain the min. edge distance is 1.5 diameters, if the loading is perpendicular to the grain the min. edge distance is 4 diameters.
-= Any Help Is Appreciated =-
Thank you,
"Grunchy" P.E.





RE: Withdrawal Resistance of Lag Screws in Wood
http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr113/Ch07.pdf
or AWC General Dowel Equations for Calculating Lateral Connection Values:Technical Report 12:
http://www.awc.org/pdf/tr12.pdf
RE: Withdrawal Resistance of Lag Screws in Wood
For lag screws in withdrawal (no lateral load):
Min. edge dist. = 1.5D
Min. end dist. = 4D
Min. spacing = 4D
RE: Withdrawal Resistance of Lag Screws in Wood
The linked resources are indispensible, thank you kindly!