Inch series · technical reference

Cross-Recessed Pan Head Screw Dimensions

Complete dimensions and tolerances from U.S. Department of Defense detail sheet MS51957F for corrosion-resistant, UNC-2A cross-recessed pan head machine screws. The eight rows shown are the complete nominal-size range of that sheet.

Source: U.S. DoD MS51957F, Table I (2 June 2022).

StandardMS51957F · UNC-2A · 2 June 2022
RevisionPrimary-source review · 2026-09
Unitsinches
MS51957F cross-recessed pan head screw Field diagram for the dimensional data in the accompanying reference table. AHLM
MS51957F Table I — complete nominal-size range
Nominal sizeTPI · UNC-2AA — head Ø max / minH — height max / minDriver size
#2560.167 / 0.1550.062 / 0.053#1
#4400.219 / 0.2050.080 / 0.070#1
#6320.270 / 0.2560.097 / 0.087#2
#8320.322 / 0.3060.115 / 0.105#2
#10240.373 / 0.3570.133 / 0.122#2
1/4 in200.492 / 0.4730.175 / 0.162#3
5/16 in180.615 / 0.5940.218 / 0.203#4
3/8 in160.740 / 0.7160.261 / 0.244#4

Illustration is not to scale. This is a controlled configuration reference; material, thread class and standard designation must match the stated scope before ordering.

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