Howmet Fastening Systems
Howmet Fastening Systems
Phone: Sales +1 800 992 4444
Technical Support +1 310 784 6409
Email: HFSTechSupport@howmet.com
Website: www.hfs.howmet.com
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THREAD: AS8879
MATERIAL:
  • Nut and Basket - Alloy or carbon steel, heat treated.
  • Clip - Cres. or ARMCO 18-2MN (NITRONIC).
FINISH:
  • Nut - F50731-(*)-(*) Cadmium plated per fed. spec. AMS-QQ-P-416, Type II, Class 2 and Kaylube molybdenum disulfide dry lubricant coated per AS5272.
    F50731X(*)-(*) Cadmium plated per fed. spec. AMS-QQ-P-416. Type II, Class 2.
  • Basket - Cadmium plated per fed. spec. AMS-QQ-P-416. Type II, Class 2.
  • Clip - Passivate per AMS2700.
FLOATABILITY: .030 min. radially from center.
PERFORMANCE: NAS 3350, Class I, except as follows:
  • Reusability of 50 cycles using plated steel bolts. Seated to max. torque values as tabulated. (Apply to "No Code" parts only).
  • Push out and twist out values as tabulated when applied. Both separately and combined.
VARIATIONS: Add "BC" for bottom countersunk rivet holes. Example: F50731-3-4BC.
F50731 Anchor Nut,Two-Lug, Floating, Self-locking Fastener
Unit of Measure
1 

Item #

A - MAX

B - MAX

C

D - MIN

H - MAX

J

K

M - MIN

V - MAX

W - REF

Push Out (LBS. MIN)

Twist Out (LBS. MIN)

Seating Torque (LBS.MAX)

Approx. Weight (LBS/100)

Thread

F50731-3-1 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.250 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.570 N/A 0.1900-32 UNJF-3B
F50731-3-2 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.312 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.610 N/A 0.1900-32 UNJF-3B
F50731-3-3 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.375 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.690 N/A 0.1900-32 UNJF-3B
F50731-3-4 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.438 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.740 N/A 0.1900-32 UNJF-3B
F50731-3-5 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.500 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.790 N/A 0.1900-32 UNJF-3B
F50731-4-1 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.295 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.570 N/A 0.2500-28 UNJF-3B
F50731-4-2 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.357 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.610 N/A 0.2500-28 UNJF-3B
F50731-5-1 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.344 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.070 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.570 N/A 0.3125-24 UNJF-3B
F50731-5-2 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.400 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.125 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.610 N/A 0.3125-24 UNJF-3B
F50731-5-5 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.586 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.313 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.790 N/A 0.3125-24 UNJF-3B
F50731X3-3 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.375 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.690 N/A 0.1900-32 UNJF-3B
F50731X3-4 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.438 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.740 N/A 0.1900-32 UNJF-3B
F50731X3-5 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.500 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.790 N/A 0.1900-32 UNJF-3B
F50731X3-6 N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.562 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.840 N/A 0.1900-32 UNJF-3B
F50731X4-1 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.295 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.570 N/A 0.2500-28 UNJF-3B
F50731X4-2 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.357 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.610 N/A 0.2500-28 UNJF-3B
F50731X4-3 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.419 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.690 N/A 0.2500-28 UNJF-3B
F50731X4-4 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.481 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.740 N/A 0.2500-28 UNJF-3B
F50731X4-5 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.543 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.790 N/A 0.2500-28 UNJF-3B
F50731X4-6 N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.605 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.840 N/A 0.2500-28 UNJF-3B
F50731X5-1 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.344 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.070 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.570 N/A 0.3125-24 UNJF-3B
F50731X5-2 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.400 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.125 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.610 N/A 0.3125-24 UNJF-3B
F50731X5-3 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.461 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.168 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.690 N/A 0.3125-24 UNJF-3B
F50731X5-4 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.524 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.250 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.740 N/A 0.3125-24 UNJF-3B
F50731X5-5 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.586 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.313 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.790 N/A 0.3125-24 UNJF-3B
F50731X5-6 N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.649 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.375 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.840 N/A 0.3125-24 UNJF-3B
F50731-3-1BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.250 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.570 N/A 0.1900-32 UNJF-3B
F50731-3-5BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.500 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.790 N/A 0.1900-32 UNJF-3B
F50731-3-6BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.562 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.840 N/A 0.1900-32 UNJF-3B
F50731-4-1BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.295 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.570 N/A 0.2500-28 UNJF-3B
F50731-4-2BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.357 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.610 N/A 0.2500-28 UNJF-3B
F50731-4-3BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.419 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.690 N/A 0.2500-28 UNJF-3B
F50731-4-4BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.481 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.740 N/A 0.2500-28 UNJF-3B
F50731-4-5BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.543 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.790 N/A 0.2500-28 UNJF-3B
F50731-4-6BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.605 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.840 N/A 0.2500-28 UNJF-3B
F50731-5-1BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.344 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.070 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.570 N/A 0.3125-24 UNJF-3B
F50731-5-2BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.400 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.125 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.610 N/A 0.3125-24 UNJF-3B
F50731-5-3BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.461 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.168 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.690 N/A 0.3125-24 UNJF-3B
F50731-5-4BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.524 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.250 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.740 N/A 0.3125-24 UNJF-3B
F50731-5-5BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.586 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.313 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.790 N/A 0.3125-24 UNJF-3B
F50731-5-6BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.649 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.375 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.840 N/A 0.3125-24 UNJF-3B
F50731X3-1BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.250 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.570 N/A 0.1900-32 UNJF-3B
F50731X3-2BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.312 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.610 N/A 0.1900-32 UNJF-3B
F50731X3-3BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.375 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.690 N/A 0.1900-32 UNJF-3B
F50731X3-4BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.438 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.740 N/A 0.1900-32 UNJF-3B
F50731X3-5BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.500 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.790 N/A 0.1900-32 UNJF-3B
F50731X3-6BC N/A 0.948 N/A 0.484 N/A 0.349-0.339 N/A 0.194 N/A 0.562 N/A 0.690-0.686 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.454 N/A 200 N/A 90 N/A 25 N/A 0.840 N/A 0.1900-32 UNJF-3B
F50731X4-1BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.295 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.070 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.570 N/A 0.2500-28 UNJF-3B
F50731X4-2BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.357 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.125 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.610 N/A 0.2500-28 UNJF-3B
F50731X4-3BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.419 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.168 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.690 N/A 0.2500-28 UNJF-3B
F50731X4-4BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.481 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.250 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.740 N/A 0.2500-28 UNJF-3B
F50731X4-5BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.543 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.313 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.790 N/A 0.2500-28 UNJF-3B
F50731X4-6BC N/A 1.292 N/A 0.584 N/A 0.505-0.495 N/A 0.254 N/A 0.605 N/A 1.002-0.998 N/A 0.103-0.098 N/A 0.375 N/A 0.037 N/A 0.554 N/A 225 N/A 160 N/A 60 N/A 0.840 N/A 0.2500-28 UNJF-3B
F50731X5-1BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.344 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.070 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.570 N/A 0.3125-24 UNJF-3B
F50731X5-2BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.400 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.125 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.610 N/A 0.3125-24 UNJF-3B
F50731X5-3BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.461 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.168 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.690 N/A 0.3125-24 UNJF-3B
F50731X5-4BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.524 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.250 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.740 N/A 0.3125-24 UNJF-3B
F50731X5-5BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.586 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.313 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.790 N/A 0.3125-24 UNJF-3B
F50731X5-6BC N/A 1.292 N/A 0.720 N/A 0.505-0.495 N/A 0.317 N/A 0.649 N/A 1.002-0.998 N/A 0.135-0.130 N/A 0.375 N/A 0.045 N/A 0.650 N/A 250 N/A 280 N/A 120 N/A 0.840 N/A 0.3125-24 UNJF-3B
Unit of Measure
1