DESCRIPTION PAGE - Sigma Fasteners

1 DESCRIPTION PAGE. Unified inch Screw Threads 15-1 to 15-5. ASTM & SAE Grade Markings for Steel Bolts & Screws 15-6. Platings & Coatings for Fasteners 15-7 to 15-8. Hex Cap Screws SAE J429 15-9 to 15-11. Steel Bar Weights 15-12. Weight Multiplier for Various Materials 15-13. Material Selection Chart 15-14. Sigma Fasteners , Inc. Section 15. UNIFIED inch SCREW THREADS-Page 1 of 5. Nominal Series1 External4 Internal4. Size & Desig- Major Pitch UN2 UNR Class Minor Pitch Major Threads In. nation Diameter Diameter Minor Minor Diameter Diameter Diameter 3 5 3.

2 Class Allow- Max Min Min Max Min Toler- Diam Diam Min Max Min Max Toler- Min ance ance Max Max ance (Ref (Ref). 0-80 or 2A --- 2B UNF. 3A --- 3B or 2A --- 2B UNC. 3A --- 3B 1-72 or 2A --- 2B UNF. 3A --- 3B 2-56 or 2A --- 2B UNC. 3A --- 3B 2-64 or 2A --- 2B UNF. 3A --- 3B 3-48 or 2A --- 2B UNC. 3A --- 3B 3-56 or 2A --- 2B UNF. 3A --- 3B 4-40 or 2A --- 2B UNC. 3A --- 3B 4-48 or 2A --- 2B UNF. 3A --- 3B 5-40 or 2A --- 2B UNC. 3A --- 3B 5-44 or 2A --- 2B UNF. 3A --- 3B 6-32 or 2A --- 2B UNC. 3A --- 3B 6-40 or 2A --- 2B UNF. 3A --- 3B 8-32 or 2A --- 2B UNC.)

3 3A --- 3B 8-36 or 2A --- 2B UNF. 3A --- 3B 10-24 or 2A --- 2B UNC. 3A --- 3B 10-32 or 2A --- 2B UNF. 3A --- 3B 12-24 or 2A --- 2B UNC. 3A --- 3B 12-28 or 2A --- 2B UNF. 3A --- 3B 1A --- 1B 1/4-20 or UNC 2A 2B 3A --- 3B -28 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 5/16-18 or UNC 1A --- 1B 2A 2B 3A --- 3B Sigma Fasteners , Inc. Section 15 Page 1. UNIFIED inch SCREW THREADS-Page 2 of 5. Nominal Series1 External4 Internal4. Size & Desig- Major Pitch UN2 UNR Class Minor Pitch Major Threads In. nation Diameter Diameter Minor Minor Diameter Diameter Diameter 3 5 3.

4 Class Allow- Max Min Min Max Min Toler- Diam Diam Min Max Min Max Toler- Min ance ance Max Max ance (Ref (Ref). 5/16-24 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 3/8-16 or UNC 1A --- 1B .0375-16 2A 2B 3A --- 3B 3/8-24 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 7/16-14 or UNC 1A --- 1B 2A 2B 3A --- 3B 7/16-20 or UNF 1A --- 1B 2A --- 2B 3A --- 3B -13 or UNC 1A --- 1B 2A --- 2B 3A --- 3B -20 or UNF 1A 04865 --- 1B 2A --- 2B 3A --- 3B 04675 9/16-12 or UNC 1A --- 1B 2A 2B 3A --- 3B 9/16-18 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 5/8-11 or UNC 1A --- 1B 2A 2B 3A --- 3B 5/8-18 or UNF 1A --- 1B.)

5 0625-18 2A --- 2B 3A --- 3B -10 or UNC 1A --- 1B 2A 2B 3A --- 3B -16 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 7/8-9 or UNC 1A --- 1B 2A 2B 3A --- 3B 7/8-14 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 1-8 or UNC 1A --- 1B 8 2A 2B 3A ---- 3B Sigma Fasteners , Inc. Section 15 Page 2. UNIFIED inch SCREW THREADS-Page 3 of 5. Nominal Series1 External4 Internal4. Size & Desig- Major Pitch UN2 UNR Class Minor Pitch Major Threads In. nation Diameter Diameter Minor Minor Diameter Diameter Diameter 3 5 3. Class Allow- Max Min Min Max Min Toler- Diam Diam Min Max Min Max Toler- Min ance ance Max Max ance (Ref (Ref).)

6 1-12 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 1-14 or UNS 1A --- 1B 2A --- 2B 3A --- 3B 1-1/8-7 or UNC 1A --- 1B 2A 2B 3A --- 3B 1-1/8-8 or UN 2A 2B 3A --- 3B 1-1/4-7 or UNC 1A --- 1B 2A 2B 3A --- 3B 1-1/4-8 or UN 2A 2B 3A --- 3B 1-1/4-12 or UNF 1A --- 1B 2A --- 2B .2039 3A --- 3B 1-3/8-6 or UNC 1A --- 1B 2A 2B 3A --- 3B 1-3/8-8 or UN 2A 2B 3A --- 3B 1-1/2-6 or UNC 1A --- 1B 2A 2B 3A --- 3B 1-1/2-8 or UN 2A 2B 3A --- 3B 1-1/2-12 or UNF 1A --- 1B 2A --- 2B 3A --- 3B 1-5/8-8 or UN 2A 15416 2B 3A --- 3B 1-3/4-5 or UNC 1A --- 1B 2A 2B 3A --- 3B 1-3/4-8 or UN 2A 2B 3A --- 3B 1-7/8-8 or UN 2A 2B 3A ---- 3B 2-4-1/2 or UNC 1A --- 1B 2A 2B 3A --- 3B 2-8 or UN 2A 19977 2B 8 3A --- 3B 2-1/4-4-1/2 UNC 1A --- 1B Sigma Fasteners , Inc.

7 Section 15 Page 3. UNIFIED inch SCREW THREADS-Page 4 of 5. Nominal Series1 External4 Internal4. Size & Desig- Major Pitch UN2 UNR Class Minor Pitch Major Threads In. nation Diameter Diameter Minor Minor Diameter Diameter Diameter 3 5 3. Class Allow- Max Min Min Max Min Toler- Diam Diam Min Max Min Max Toler- Min ance ance Max Max ance (Ref (Ref). or 2A 2B 3A --- 3B 2-1/4-8 or UN 2A 2B 3A --- 3B 2-1/2-4 or UNC 1A --- 1B 2A 2B 3A --- 3B 2-1/2-8 or UN 2A 2B 3A --- 3B 2-3/4-4 or UNC 1A --- 1B 2A 2B 3A --- 3B 2-3/4-8 or UN 2A 2B 3A --- 3B 3-4 or UNC 1A --- 1B 4 2A 2B 3A --- 3B 3-8 or UN 2A 2B 239188 29299 8 3A --- 3B 3-1/4-4 or UNC 1A --- 1B 2A 2B 3A --- 3B 3-1/4-8 or UN 2A 2B 030113 3A --- 3B 3-1/2-4 or UNC 1A --- 1B 2A 2B 3A --- 3B 3-1/2-8 or UN 2A 2B 3A --- 3B 3-3/4-4 or UNC 1A --- 1B 2A 2B 3A --- 3B 3-3/4-8 or UN 2A 2B 3A --- 3B 4-4 or UNC 1A --- 1B 4 2A 2B 3A --- 3B 4-8 or UN 2A)

8 2B 8 3A --- 3B Sigma Fasteners , Inc. Section 15 Page 4. ASTM AND SAE GRADE MARKINGS. FOR STEEL BOLTS AND SCREWS. Ult. Tensile Grade Bold & Screw Yield Specification Material Strength Marking Size (In.) PSI. Min PSI. SAE-Grade 1 1/4 thru 1-1/2 33,000 60,000. Grade A Low Carbon Steel 1/4 thru 1-1/2 33,000 60,000. ASTM-A307 1018-1022 Steel over 1-1/2 thru 4 ---- 55,000. 1/4 thru 3/4 55,000 74,000. SAE-Grade 2. over 3/4 thru 1-1/2 33,000 60,000. 1/4 thru 1-1/2 85,000 120,000. SAE-Grade 5. over 1-1/2 thru 4 74,000 105,000. Medium Carbon Steel Quenched & Tempered 1038 Steel 1/4 thru 1 85,000 120,000.

9 ASTM-A449 over 1 thru 1-1/2 74000 105,000. over 1-1/2 thru 3 55,000 90,000. Medium Carbon Steel 1/2, 5/8, 3/4 85,000 120,000. ASTM-A325 Quenched & Tempered 7/8, 1 78,000 115,000. 1038 Steel 1-1/8 thru 1-1/2 74,000 105,000. Alloy Steel, ASTM-A354 1/4 thru 2-1/2 130,000 150,000. Quenched & Tempered Grade BD over 2-1/2 thru 4 115,000 140,000. 4140/4340 Alloy Steel Alloy Steel, ASTM-A354 1/4 thru 2-1/2 109,000 125,000. Quenched & Tempered Grade BC over 2-1/2 99,000 115,000. 4140/4145 Alloy Steel ASTM-A193 Alloy Steel, 2-1/2 & under 105,000 125,000.

10 Grade B7 Quenched & Tempered 2-1/2 thru 4 95,000 115,000. Medium Carbon Alloy Steel SAE-Grade 8 1/4 thru 1-1/2 120,000 150,000. Quenched & Tempered Alloy Steel, 1/2 thru 2-1/2 120,000 150,000. ASTM-A490. Quenched & Tempered over 2-1/2 thru 4 105,000 140,000. Sigma Fasteners , Inc. Section 15 Page 5. PLATINGS AND COATINGS FOR Fasteners . Cadmium Plating (ASTM B766). An electrolytically deposited, silver-gray plating which provides exceptionally good protection against corrosion, particularly in a salt atmosphere. Chromate Clear Dip is a protective film dip applied after electroplating, and gives additional corrosion protection and a bright, shiny appearance which resists staining and finger marks.