- To suck in one member against an attachment surface, predrill the member the same size as lag bolt size. The surface is predrilled with a smaller hole. This way, the bolt slides in the hole in the member, sucking it in to the attachment surface.
Predrill Hole Size
- For 1/2" bolts- 1/4". Softwood assumed.
- 3/8" bolts - 11/64" predrill
- Strengh is 450 lb per inch of thread in southern pine -