No. 1/4 - 20  x  3/8" U.N.R.C. Coarse Thread
Product Code Number 19054

Nominal Size or Basic Screw Diameter Head
Diameter		 Head Height Protrusion Gage Diameter Protrusion Hexagon Socket Size Key Engagement Fillet Transition Diameter Length, Overall
Theo. Sharp Max Abs. Min Ref Max Min Max Min Nom Min Max
1/4 (0.2500) 0.531 0.480 0.161 0.424 0.423 0.059 0.046 5/32 (0.156) 0.111 0.280 3/8
SEE NOTES 1 3 4 5 5 18    13 6, 7, 8

NOTES: (8) Length Tolerances (16) Threads
(1) Nominal Size (9) Thread Length (17) Material
(2) Body (10) Grip Gaging Length (18) Hexagon Socket Dimension
(3) Head Diameter (11) Body Length (19) Dimensional Conformance
(4) Head Height (12) Screw Point Chamfer  (20) Designation
(5) Protrusion (13) Fillet (21) Gaging of Hexagon Sockets
(6) Length (14) Bearing Surface (22) Screw Thread Limits
(7) Standard Lengths  (15) Concentricity (23) Mechanical Properties

Reprinted from ASME/ANSI B18.3 by permission of The American Society of Mechanical Engineers.  All rights reserved.  For a full copy of the standards, contact the ASME at http://www.asme.org/codes/.

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