Machine Screws

Slotted Flat Head Machine Screws

Dimensions of Slotted 100-deg Flat Countersunk Head Screws
(Machine Screws Only)

Nominal Size or Basic Screw Diameter		A		H	J		T		F		G
		Head Diameter		Head Height	Slot Width		Slot Depth		Protrusion Above Gaging Diameter		Gaging Diameter
		Max	Min	Ref	Max	Min	Max	Min	Max	Min	Gaging Diameter
0000	0.0210	0.040	0.035	0.009	0.008	0.005	0.008	0.004	[Note (4)]	[Note (4)]	[Note (4)]
000	0.0340	0.060	0.055	0.014	0.012	0.008	0.011	0.007	[Note (4)]	[Note (4)]	[Note (4)]
00	0.0470	0.087	0.080	0.020	0.017	0.010	0.013	0.008	[Note (4)]	[Note (4)]	[Note (4)]
0	0.0600	0.112	0.095	0.026	0.023	0.016	0.013	0.008	0.020	0.012	0.074
1	0.0730	0.137	0.118	0.031	0.026	0.019	0.016	0.010	0.021	0.013	0.098
2	0.0860	0.162	0.142	0.037	0.031	0.023	0.019	0.012	0.022	0.014	0.121
3	0.0990	0.187	0.165	0.043	0.035	0.027	0.022	0.014	0.024	0.015	0.144
4	0.1120	0.212	0.188	0.049	0.039	0.031	0.024	0.017	0.025	0.016	0.167
6	0.1380	0.262	0.235	0.060	0.048	0.039	0.030	0.022	0.028	0.017	0.214
8	0.1640	0.312	0.282	0.072	0.054	0.045	0.036	0.027	0.031	0.019	0.261
10	0.1900	0.362	0.329	0.083	0.060	0.050	0.042	0.031	0.034	0.021	0.307
1/4	0.2500	0.477	0.437	0.110	0.075	0.064	0.055	0.042	0.040	0.025	0.415
5/16	0.3125	0.597	0.550	0.138	0.084	0.072	0.069	0.053	0.047	0.030	0.526
3/8	0.3750	0.717	0.662	0.165	0.094	0.081	0.083	0.065	0.053	0.034	0.638

Notes:
1. Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted.
2. Tabulated values determined from formula for maximum H in Nonmandatory Appendix C.
3. No tolerance for gaging diameter is given. If the gaging diameter of the gage used differs from tabulated value, the protrusion will be affected accordingly and the proper protrusion values must be recalculated using the formulas shown in Appendix I.
4. Not practical to gage.
5. For recess dimensions, refer to Table 4.
6. For slot inspection, see para. 2.1.4.