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FLAT HEAD SELF TAPPING SCREW
Head Dimensions
82° Flat Head Self Tapping Screws 82° Undercut Flat Head Self Tapping Screws Square Drive Flat Head Self Tapping Screws Torx® Drive Flat Head Self Tapping Screws



Head Dimensions for 82° Flat Head Self-Tapping Screws - ANSI B18.6.4
Nominal Size These
Lengths or
Shorter are
Undercut		 A H J T M R N F G Phillips
Driver
Size
Head
Dimensions		 Slot Dimensions Phillips Dimensions Protrusion Above
Gaging Diameter		 Gaging Diameter
Diameter Height Width Depth Dia Depth Width
Types
A and AB		 Other
Types		 Max Min Max Min Max Min Max Min Ref Ref Ref Max Min
0 3/16 1/8 .112 .096 .035 .026 .023 .016 .015 .010 .062 .035 .014 .026 .016 .078 0
1 3/16 5/32 .137 .120 .043 .033 .026 .019 .019 .012 .070 .043 .015 .028 .016 .101 0
2 3/16 3/16 .162 .144 .051 .040 .031 .023 .023 .015 .096 .055 .017 .029 .017 .124 1
4 1/4 1/4 .212 .191 .067 .055 .039 .031 .030 .020 .122 .081 .018 .032 .019 .172 1
5 1/4 1/4 .237 .215 .075 .062 .043 .035 .034 .022 .148 .074 .027 .034 .020 .196 2
6 5/16 5/16 .262 .238 .083 .069 .048 .039 .038 .024 .168 .094 .029 .036 .021 .220 2
7 3/8 3/8 .287 .262 .091 .076 .048 .039 .041 .027 .176 .102 .030 .037 .022 .243 2
8 7/16 7/16 .312 .285 .100 .084 .054 .045 .045 .029 .182 .110 .030 .039 .023 .267 2
10 1/2 1/2 .362 .333 .116 .098 .060 .050 .053 .034 .198 .124 .032 .042 .025 .313 2
12 9/16 9/16 .412 .380 .132 .112 .067 .056 .060 .039 .262 .144 .035 .045 .027 .362 3
14 5/8 - .462 .427 .148 .126 .075 .064 .068 .044 .276 .160 .036 .049 .029 .410 3
1/4 5/8 5/8 .477 .442 .153 .131 .075 .064 .070 .046 .276 .160 .036 .050 .029 .424 3
5/16 13/16 5/8 .597 .556 .191 .165 .084 .072 .088 .058 .358 .205 .061 .057 .034 .539 4
3/8 - 5/8 .717 .670 .230 .200 .094 .081 .106 .070 .386 .234 .065 .065 .039 .653 4
Note: The length of a flathead screw is always measured by the total length of the screw,
from the top of the head to the extreme end of the threads.




Head Dimensions for Undercut Flat Head Self Tapping Screws - ANSI B18.6.4
Nominal
Size		 These
Lengths
or
Shorter
are
Undercut		 A H J T M R N F G Phillips
Driver
Size
Head Dimensions Slot Dimensions Recess Dimensions Protrusion
Above Gaging
Diameter		 Gaging
Diameter
Diameter Height Width Depth Dia Depth Width
Types
A and AB		 Other
Types		 Max Min Max Min Max Min Max Min Ref Ref Ref Max Min
0 3/16 1/8 .112 .096 .025 .018 .023 .016 .011 .007 .069 .035 .014 - - - 0
1 3/16 5/32 .137 .120 .031 .023 .026 .019 .014 .009 .070 .043 .015 - - - 0
2 3/16 3/16 .162 .144 .036 .028 .031 .023 .016 .011 .088 .048 .017 .029 .017 .124 1
4 1/4 1/4 .212 .191 .047 .038 .039 .031 .022 .014 .110 .070 .018 .032 .019 .172 1
6 5/16 5/16 .262 .238 .059 .048 .048 .039 .027 .017 .140 .066 .025 .036 .021 .220 2
7 3/8 3/8 .287 .262 .064 .053 .048 .039 .030 .019 .148 .074 .027 .037 .022 .243 2
8 7/16 7/16 .312 .285 .070 .058 .054 .045 .032 .021 .168 .094 .029 .039 .023 .267 2
10 1/2 1/2 .362 .333 .081 .068 .060 .050 .037 .024 .182 .110 .030 .042 .025 .313 2
12 9/16 9/16 .412 .380 .092 .078 .067 .056 .043 .028 .226 .110 .030 .045 .027 .362 3
1/4 5/8 5/8 .477 .442 .107 .092 .075 .064 .050 .032 .244 .124 .032 .050 .029 .424 3
5/16 13/16 5/8 .597 .556 .134 .116 .084 .072 .062 .041 .310 .157 .053 .057 .034 .539 4
3/8 - 5/8 .717 .670 .161 .140 .094 .081 .075 .049 .358 .205 .061 .065 .039 .653 4
Note: The length of a flathead screw is always measured by the total length of the screw,
the top of the head to the extreme end of the threads.



Head Dimensions for Square Drive Flat Head Self Tapping Screws - IFI
Nominal Size
Or
Basic Screw
Diameter		 A M T Driver
Size		 F
Head Diameter Recess Square Recess Depth Gauge
Penetration
Max Min Max Min Max Min Max Min
4 .1120 .212 .191 .071 .0696 .073 .063 0 .038 .032
6 .1380 .262 .238 .091 .090 .113 .105 1 .065 .057
8 .1640 .312 .285 .1126 .111 .140 .119 2 .075 .065
10 .1900 .362 .333 .1126 .111 .140 .119 2 .075 .065
12 .2160 .412 .380 .133 .1315 .165 .155 3 .095 .085
1/4 .2500 .477 .442 .133 .1315 .165 .155 3 .095 .085
5/16 .3125 .597 .556 .191 .1895 .201 .191 4 .100 .090
The recess has a square center opening, slightly tapered side walls and a conical bottom.
Note: The length of a flathead screw is always measured by the total length of the screw,
the top of the head to the extreme end of the threads.



Head Dimensions for Torx® Drive Flat Head Self Tapping Screws - Camcar
Nominal Size G T B F Maximum
Penetration
of "No-Go"
Gauge
(Fallawat)		 Torx®
Driver
Size
Head Diameter Head Height Recess
Diameter		 Gauge
Penetration
Max Sharp Min Sharp Abs Min Ref Ref Min
4 .225 .209 .195 .067 .094 .028 .019 T8
6 .279 .257 .244 .083 .111 .035 .022 T10
8 .332 .308 .282 .100 .132 .040 .026 T15
10 .385 .359 .340 .116 .155 .050 .031 T20
1/4 .507 .447 .452 .153 .200 .075 .040 T27

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Self Tapping Screws
Smith Fastener Company, A California Corporation - 3613 East Florence Avenue, Bell, California, 90201 - Phone: ( 323 ) 587-0382 - FAX: ( 323 ) 587-8712 - E-mail: sales@smithfast.com - Copyright © 2000 by Smith Fastener Company - Last updated: May 19th, 2006 - http://www.smithfast.com/flattapping.htm