Serrated Hex Flange Lock Nuts: Dimensions & Specifications

Serrated Hex Flange Lock Nuts Drawing

Serrated Hex Flange Lock Nuts (ASME B18.16.4-2008)

Nominal
Size or Basic Major Diameter of Thread

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 Number of Thread Starts Width Across Flats
(F)		 Width Across Corners
(G)		 Flange Diameter
(B)		 Nut Thickness
(H)		 Wrenching
Height
(K)		 Flange
Thickness(J)
Max Min Max Min Max Min Max Min Min
 Min
4 0.1120 0.250 0.241 0.289 0.275 0.386 0.370 0.160 0.147 - 0.02
6 0.1380 0.312 0.302 0.361 0.342 0.422 0.406 0.171 0.156 0.10 0.02
8 0.1640 0.344 0.334 0.397 0.381 0.469 0.452 0.203 0.187 0.13 0.02
10 0.1900 0.375 0.365 0.433 0.416 0.500 0.480 0.219 0.203 0.13 0.03
12 0.2160 0.438 0.428 0.505 0.488 0.594 0.574 0.236 0.222 0.14 0.04
1/4 0.2500 0.438 0.428 0.505 0.488 0.594 0.574 0.236 0.222 0.14 0.04
5/16 0.3125 0.500 0.489 0.577 0.557 0.680 0.660 0.283 0.268 0.17 0.04
3/8 0.3750 0.562 0.551 0.650 0.628 0.750 0.728 0.347 0.330 0.23  
7/16 0.4375 0.688 0.675 0.794 0.768 0.937 0.910 0.395 0.375 0.26 0.04
1/2 0.5000 0.750 0.736 0.866 0.840 1.031 1.000 0.458 0.437 0.31 0.05
9/16 0.5625 0.875 0.861 1.010 0.982 1.188 1.155 0.506 0.483 0.35 0.05
5/8 0.6250 0.938 0.922 1.083 1.051 1.281 1.248 0.569 0.545 0.40 0.05
3/4 0.7500 1.125 1.088 1.299 1.240 1.500 1.460 0.675 0.627 0.46 0.06
7/8 0.8750 1.179 1.166 1.361 1.295 1.682 - 0.786 0.742 - 0.11

 *ASME specifies to #6 through 3/4" diameters.

Description

Hex nut flaring out from the bottom of the nut with an enlarged circular base. The flange's bearing
surface has serrations that displace material on the surface of the mating when the nut is wrenched in place,
forming a connection that resists loosening. 
Applications/
Advantages		 Requires more toughening torque to make the nut loosen than to tighten.
Will span holes that are too large or poorly aligned. Flange offers the clamp-force ratio of a more
standardized bearing-stress than other low-carbon nuts. Does not gall screw threads.
Material

Steel

 Stainless

Nuts are produced from carbon steel that meets the following
chemical composition requirements—Carbon: max. 0.47% ; Phosphorus: max. 0.12% ; Sulfur: max. 0.23%.

18-8 Stainless Steel
Heat Treatment

Nuts are hardened to the correct hardness to guarantee
adequate gripping power for the serrations.

-
Case Hardness

Rockwell HR15N 78 - 90

-
Plating

Steel flange nuts are provided in different finishes,
including clear zinc, black zinc and black oxide.

Stainless flange nuts are normally
supplied without extra plating.