• THREAD SERIES DESIGNATOR : UNC
  • NOMINAL THREAD DIAMETER : 0.250 INCHES
  • THREAD QUANTITY PER INCH : 20​​​​​​​
  • THREAD CLASS : 2A​​​​​​​
  • THREAD DIRECTION : RIGHT-HAND​​​​​​​
  • THREAD LENGTH : 0.719 INCHES MINIMUM AND 0.875 INCHES MAXIMUM​​​​​​​ 
  • FASTENER LENGTH : 0.844 INCHES MINIMUM AND 0.875 INCHES MAXIMUM​​​​​​​ 
  • MATERIAL : STEEL OVERALL 
  • MATERIAL DOCUMENT AND CLASSIFICATION : SAE J429 GRADE 8 ASSN STD SINGLE MATERIAL RESPONSE OR ASTM A354 GRADE BD ASSN STD SINGLE MATERIAL RESPONSE OVERALL
  • SURFACE TREATMENT : ZINC AND CHROMATE OVERALL​​​​​​​
  • SURFACE TREATMENT DOCUMENT AND CLASSIFICATION : ASTM B633 TY 2 SC 3 ASSN STD SINGLE TREATMENT RESPONSE OVERALL​​​​​​​
  • HARDNESS RATING : 32.0 ROCKWELL C MINIMUM AND 38.0 ROCKWELL C MAXIMUM OVERALL
  • MINIMUM TENSILE STRENGTH : 150000 POUNDS PER SQUARE INCH
  • HEAD STYLE  : C1 HEXAGON 
  • HEAD HEIGHT  : 0.150 INCHES MINIMUM AND 0.163 INCHES MAXIMUM​​​​​​​
  • WIDTH BETWEEN FLATS : 0.428 INCHES MINIMUM AND 0.438 INCHES MAXIMUM​​​​​​​
  • SURFACE FINISH : 63.0 MICROINCHES THREADS 
  • III END ITEM IDENTIFICATION : AVIATION ENGINE TEST SYSTEMS (AETS);SUPPORT EQUIPMENT, B-1 AIRCRAFT;COMMUNICATIONS TERMINAL, SATELLITE AN/GSC-39(V)1;FIRE PUMPS;STREAM (STD. TENSIONED REPLENISHMENT AT SEA METHOD);SHIPBOARD MATERIAL HANDLING EQUIPMENT (MHE);TORPEDO, MK 48;CHILLED WATER A/C SYSTEMS;SYSTEMS, JP-5 AVIATION FUELS;MISSILE, AIR INTERCEPT, SIDEWINDER (AIM-9)

Hexagon Head Cap Screw

  • Fastener Length: 27/32", Thread: 1/4-20, Thread Length: 23/32", hexagon head, coarse thread