FASTENERS 101™
Fastener Reference Tables

Conversions, Hardness, Thread Pitch, Tensile Strength, & Sizing Charts

The tables below are provided as a general guide to help you better understand metric and imperial measurements. Always refer to project specifications and consult an engineer to ensure that your application is appropriate.

Printable Conversion Charts and Quick Reference Sheets



DIAMETER & THREAD PITCH CONVERSIONS

INCH METRIC CONVERSION (Diameter)
COARSE (UNC) FINE (UNF) COARSE (UNC) FINE (UNF) INCH METRIC
1/4"-20 1/4"-28 M6-1.00 M6-0.75 1/4" M6
5/16"-18 5/16"-24 M8-1.25 M8-1.00 5/16" M8
3/8"-16 3/8"-24 M10-1.50 M10-1.25 3/8" M10
7/16"-14 7/16"-20 M12-1.75 M12-1.50 1/2" M12
1/2"-13 1/2"-20 M14-2.00 M14-1.50 5/8" M16
9/16"-12 9/16"-18 M16-2.00 M16-1.50 3/4" M20
5/8"-11 5/8"-18 M20-2.50 M20-1.50 7/8" M22
3/4"-10 3/4"-10 M22-2.50 M22-1.50 1" M24
7/8"-9 7/8"-14 M24-3.00 M24-2.00 1-1/8" M27
1"-8 1"-14 M27-3.00 M27-2.00 1-1/4" M30
1-1/8"-7 1-1/8"-12 M30-3.50 M30-2.00 1-3/8" M33
1-1/4"-7 1-1/4"-12 M36-4.00 M36-2.00 1-1/2" M36
1-3/8"-6 1-3/8"-12 M42-4.50 M42-2.00 1-3/4" M42
1-1/2"-6 1-1/2"-12 M48-5.00 M48-2.00 2" M48


US Nut Size Charts

PDF Thumbnail US-serrated-flange-nut size chart US Serrated Flange Nut Size Chart (PDF) - Print Friendly, 108Kb
PDF Thumbnail US nylon inserted hex lock nut size chart US Nylon Inserted Hex Lock Nut Size Chart (PDF) - Print Friendly, 176Kb
PDF Thumbnail US hex jam nut size chart US Hex Jam Nut Size Chart (PDF) - Print Friendly, 100Kb
PDF Thumbnail US machine screw hex nut size chart US Machine Screw Hex Nut Size Chart (PDF) - Print Friendly, 57Kb

Metric Nut Size Charts

PDF Thumbnail metric flange nut size chart Metric Serrated Flange Nut Size Chart (PDF) - Print Friendly, 55Kb
PDF Thumbnail metric hex jam nut size chart Metric Hex Jam Nut Size Chart (PDF) - Print Friendly, 108Kb
PDF Thumbnail metric hex nut size chart Metric Hex Nut Size Chart (PDF) - Print Friendly, 137Kb

USS & SAE Washer Size Charts

PDF Thumbnail USS flat washer size chart USS FLAT WASHERS Size Chart (PDF) - Print Friendly, 173Kb
PDF Thumbnail SAE flat washer size chart SAE FLAT WASHERS Size Chart (PDF) - Print Friendly, 173Kb

Metric Washer Size Charts

PDF Thumbnail metric flat washer size chart METRIC FLAT WASHERS Size Chart (PDF) - Print Friendly, 163Kb
 


TENSILE STRENGTH COMPARISON

Imperial Grades

IBF/IN2 (PSI)

Metric Classes

MPA (N/MM2)
L9 -- 180,000 PSI -- HIGH TENSILE CLASS 12.9 -- 1,200 MPA -- HIGH TENSILE
SAE GRADE 8 -- 150,000 PSI -- HIGH TENSILE CLASS 10.9 -- 1,034 MPA-- HIGH TENSILE
SAE GRADE 5 -- 120,000 PSI -- HIGH TENSILE CLASS 8.8 -- 827 MPA-- HIGH TENSILE
STAINLESS CLASS 80 (304--316) -- 116,000 PSI STAINLESS CLASS 80 (304-316) -- 800 MPA
STAINLESS CLASS 70 (304-316) 101,000 PSI STAINLESS CLASS 70 (304-316) -- 700 MPA

CLASS 5.8 -- 520 MPA
STAINLESS CLASS 50 (NO MARKINGS) -- 72,000 PSI STAINLESS CLASS 50 (NO MARKINGS) -- 500 MPA
LOW CARBON -- 62,000 PSI 427 MPA
58,015 PSI CLASS 4.6 - 400 MPA




HARDNESS


Screw Type
S Surface &
C Case Hardness
Core Hardness
(After Temper)
Material
Tapping Type A/AB/B (S)Rockwell C45 min Rockwell C28-38 AISI 1016-1024 or Equivalent Steel
Self Tapping Hi-Lo (C)Rockwell C45 min Rockwell C28-36 AISI 1019-1022 or Equivalent Steel
Thread Cutting Type 25/23/F (S)Rockwell C45 min Rockwell C28-38 AISI 1016-1024 or Equivalent Steel
Type F Torx Floorboard Screws (S)Rockwell C45 min Rockwell C28-38 AISI 1016-1024 or Equivalent Steel
Tri-Lobular Thread Rolling (C)Rockwell C45 min Rockwell C28-38 AISI 1016-1024 or Equivalent Steel
Self Piercing Screws (S)Rockwell C45 min Rockwell C28-38 AISI 1018-1022 or Equivalent Steel
Self Drilling Screws (C)Rockwell C52-58 Rockwell C32-40 AISI 1016-1024 or Equivalent Steel



Screw Size Conversion Chart

Screw Size Fraction Decimal
#1 1/16 0.0625
#2 5/64 0.0781
#3 3/32 0.0937
#4 7/64 0.1093
#5 1/8 0.125
#6 9/64 0.1406
#8 5/32 0.1562
#9 11/64 0.1718
#10 3/16 0.1875
#11 13/64 0.1718
#12 7/32 0.2187
#13 15/64 0.2343
#14 1/4 0.25
#16 17/64 0.2656
#18 17/64 0.2968
#20 5/16 0.3125
#24 3/8 0.375

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