Free Table Showing Width of Slot for Slotted Screws

WIDTH OF SLOT FOR SLOTTED SCREWS

DIAMETER OF HEAD

	FH Pic	OH Pic	Round Head Pic		TH Pic	BH Pic	Fillister Head Pic		PH Pic
Screw Sizes	Flat Head Oval Head		Round Head		Truss Head	Binding Head	Fillister Head		Pan Head	Width of Slot
Screw Sizes	Wood	Machine	Wood	Machine	Truss Head	Binding Head	Cap	Machine	Pan Head	Width of Slot
1	.146	.146	.138	.138				.118		.026
	.130	.130	.122	.122				.104		.019
2	.172	.172	.162	.162	.194	.181		.140	.167	.031
	.156	.156	.146	.146	.180	.171		.124	.155	.023
3	.199	.199	.187	.187	.226	.208		.161	.193	.035
	.181	.181	.169	.169	.211	.197		.145	.180	.027
4	.225	.225	.211	.211	.257	.235		.183	.219	.039
	.207	.207	.193	.193	.241	.223		.166	.205	.031
5	.252	.252	.236	.236	.289	.263		.205	.245	.043
	.232	.232	.217	.217	.272	.249		.187	.231	.035
6	.279	.279	.260	.260	.321	.290		.226	.270	.048
	.257	.257	.240	.240	.303	.275		.208	.256	.039
7	.305		.285		.352				.296	.048
	.283		.264		.333				.281	.039
8	.332	.332	.309	.309	.384	.344		.270	.322	.054
	.308	.308	.287	.287	.364	.326		.250	.306	.045
9	.358		.334							.054
	.334		.311							.045
10	.385	.385	.359	.359	.448	.339		.313	.373	.060
		.359	.334	.334	.425	.378		.292	.357	.050
12	.438	.438	.408	.408	.511	.454		.357	.425	.067
	.410	.410	.382	.382	.487	.430		.334	.407	.056
14	.491		.457							.075
	.461		.424							.064
1/4"		.507		.472	.573	.513	.375	.414	.492	.075
		.477		.443	.546	.488	.363	.389	.473	.064
16	.544		.506							.075
	.512		.476							.064
18	.597		.555							.084
	.563		.523							.072
5/16"		.635		.590	.698	.641	.437	.518	.615	.084
		.600		.557	.666	.609	.424	.490	.594	.072
20	.650		.604							.084
	.614		.570							.072
24	.756		.702							.094
	.716		.664							.081
3/8"		.762		.708	.823	.769	.562	.622	.740	.094
		.722		.670	.787	.731	.547	.590	.716	.081

When ordering slotted bits, please remember that head sizes and slot widths of hardened, self-tapping, and sheet metal screws do not conform to the same specifications as standard wood or machine screws described in the chart below. Also, because of variations in these dimensions among screws from different manufacturers, bits should be ordered to head and slot size rather than screw size.

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