AIA/NAS 1352-2009 pdf download SCREW, CAP, SOCKET HEAD PRRT STANDQRD UNDRILLED FWD DRILLED, PLAIN AND SELF-LOCKING AND EAT-RESISTANT STEEL. UNRC-3A AND UNFX-2Q
(a) “M” MIN. (5 THREAD PITCHES) = REGION OF MINIMUM ENGAGEMENT WITH FULL FEMALE THREAD REQUIRED TO MEET MIL-DTL-1 8240 REQUIREMENTS.
LOCKING ELEMENT WITHIN “M” REGION MUST DEVELOP REQUIRED TORQUE WHEN TESTED IN ACCORDANCE WITH MIL-DTL-1 8240.
LENGTH OR DIAMETER OF LOCKING ELEMENT MAY BE MORE OR LESS THAN “M” PROVIDING ALL OTHER REQUIREMENTS ARE MET.
(b) “N” = ONE (1 ) COMPLETE THREAD PLUS UNTHREADED PORTION OF END. FOR EASE OF STARTING, LOCKING ELEMENT SHALL NOT BE EFFECTIVE WITHIN THIS AREA.
(c) SCREWS WHICH HAVE A LENGTH LESS THAN THE MINIMUM BASIC THREAD LENGTH, SHALL BE THREADED AS CLOSE TO HEAD AS PRACTICABLE. FOR SCREWS WHICH HAVE A LENGTH GREATER THAN THE MINIMUM BASIC THREAD LENGTH, THE BODY AND GRIP LENGTH SHALL BE IN ACCORDANCE WITH ASME B1 8.3.
(d) DRILLED HOLE DATA IN ACCORDANCE WITH PROCUREMENT SPEC FF-S-86.
PARTS SHALL HAVE DRILLED HEADS IF SPECIFIED BY CODE H.
SCREW SIZES 04 AND 06 SHALL HAVE TWO (2) DRILLED HOLES SPACED 1 80°.
SCREW SIZES 08 THRU 1 6 SHALL HAVE SIX (6) DRILLED HOLES SPACED 60°.
(DRILLED HOLES NOT APPLICABLE TO SCREW SIZES BELOW 04 AND ABOVE 1 6).
(e) IDENTIFICATION LETTER “N” IMPRESSED ON THE TOP OR SIDE OF THE HEAD, FOR SCREW SIZES 04 AND LARGER ONLY, TO DENOTE HEAT-RESISTANT STEEL.
(f) THE INTERSECTION OF THE TOP AND SIDE OF THE HEAD MAY BE CHAMFERED OR RADIUSED AT THE MANUFACTURER’S OPTION PER ASME B1 8.3.
(g) THE FILLET SHALL BE IN ACCORDANCE WITH ASME B1 8.3.
(h) MINIMUM BREAKING STRENGTH VALUES ARE BASED ON 1 80 KSI HEAT TREATMENT. LINED THROUGH STRENGTH VALUES WERE BASED ON 1 70 KSI.
THREADS: IN ACCORDANCE WITH PROCUREMENT SPECIFICATION. UNRC-3A FOR NOMINAL DIAMETERS 1 .000 INCH AND SMALLER. UNRC-2A FOR NOMINAL DIAMETERS GREATER THAN 1 .000 INCH.
MATERIAL: ALLOY STEEL IN ACCORDANCE WITH PROCUREMENT SPEC FF-S-86.
CORROSION-RESISTANT STEEL IN ACCORDANCE WITH PROCUREMENT SPEC FF-S-86.
HEAT-RESISTANT STEEL CONFORMING TO CHEMISTRY OF AMS5731 (UNS S66286) OR AMS5737 (UNS S66286) COLD WORKED AND AGE HARDENED TO MEET THE FASTENER REQUIREMENTS OF FF-S-86 AND THIS STANDARD.
FINISH: ALLOY STEEL – CADMIUM PLATE IN ACCORDANCE WITH AMS-QQ-P-41 6, TYPE II, CLASS 2.
– BLACK OXIDE IN ACCORDANCE WITH MIL-DTL-1 3924, CLASS I.
CORROSION RESISTANT STEEL – CADMIUM PLATE IN ACCORDANCE WITH AMS-QQ-P-41 6, TYPE I,CLASS 2.
– SILVER FLASH IN ACCORDANCE WITH AMS241 1 .
– PASSIVATE IN ACCORDANCE WITH AMS2700, METHOD 1 , TYPE 6 OR TYPE 7,CLASS 1 .
CODE: MATERIAL CODE AFTER BASIC NUMBER. “-” = ALLOY STEEL.
“C” = CORROSION-RESISTANT STEEL.
“N” = HEAT-RESISTANT STEEL.
FIRST DASH NUMBER DESIGNATES SCREW THREAD SIZE AS TABULATED.