Wood Screws

Conventional wood screws commonly used are the Countersunk/flat head (252:2A), round head for attaching metal to wood (252:2B), and raised/oval head (252:2c), obtainable in brass, steel, japanned (round head), coppered, chrome, BMA finish, etc. according to the type. The length of a screw is taken as all that part of the screw concealed by the wood, thus the length of a countersunk screw will be the overall length (252:1), round head from under the head, and raised head from the junction of the raised head with the counter-sinking. The diameter of all screw-heads is twice the diameter of the shank, the angle of the countersink 45° to the central axis, and the length of the actual thread three-fifths (0.6) of the stated length. A useful formula for the determination of the stated gauge number is: diameter of head in 1/32 in — 3 = screw gauge number; thus diameter of head 13/32in — 3 = 10 which is the gauge number. The diameter of the shank can be calculated from the gauge number by taking the known diameter of a No. 1 screw as 0.066 in with an additional 0.014 in for each subsequent increase in the number of the gauge; thus a No. 8 screw will be 0.066 in (No. 1 screw) - 7(0.014) or 0.164 in diameter. This will be the size of the hole required for a No. 8 screw shank, but as drill sizes are in 1/64 in the nearest approximate size will have to be used, and the

252 Screw types, etc.

formula commonly adopted is to add 3 to the gauge number to give the size of the drill in 1/64 in. Thus No. 8 screw plus 3 = 11/64 in which is 0.172 in in diameter. The table gives the usual drill sizes for the shank or clearance hole, and for the hole to receive the thread.

Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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