Hex Bolt Identifying Marks, Material Grade and Mechanical Properties

Are you confused about the modest hex bolt, or are you wondering what all those marks mean?  This table will help you identify any hex bolt right on the nuts, and it will also tell you about the material grade and mechanical properties.  What more could you ask for from a super boring table?

Hex Bolt Identification
Grade Mark
Specification Fastener
Description
Material Nominal Size
Range (in.)
Mechanical Properties
Proof Load
(psi)
Yield Strength
Min (psi)
Tensile Strength
Min (psi)

No
Grade
Mark
SAE J429
Grade 1
Bolts,
Screws,
Studs
Low or Medium Carbon Steel 1/4 thru 1-1/2 33,000 36,000 60,000
ASTM A307
Grades A&B
Low Carbon Steel 1/4 thru 4
SAE J429
Grade 2
Low or Medium Carbon Steel 1/4 thru 3/4 Over 3/4 to 1-1/2 55,000
33,000
57,000
36,000
74,000
60,000

No
Grade
Mark
SAE J429
Grade 4
Studs Medium Carbon Cold Drawn Steel 1/4 thru 1-1/2 100,000 115,000

B5
ASTM A193
Grade B5
AISI 501 1/4 Thru 4 80,000 100,000

B6
ASTM A193
Grade B6
AISI 410 85,000 110,000

B7
ASTM A193
Grade B7
AISI 4140, 4142, OR 4105 1/4 thru 2-1/2
Over 2-1/2 thru 4
Over 4 thru 7


105,000
95,000
75,000
125,000
115,000
100,000

B16
ASTM A193
Grade B16
CrMoVa Alloy Steel 105,000
95,000
85,000
125,000
115,000
100,000

B8
ASTM A193
Grade B8
AISI 304 1/4 and larger 30,000 75,000

B8C
ASTM A193
Grade B8C
AISI 347

B8M
ASTM A193
Grade B8M
AISI 316

B8T
ASTM A193
Grade B8T
Bolts,
Screws,
Studs for High-Temperature Service
AISI 321 1/4 and larger 30,000 75,000

B8
ASTM A193
Grade B8
AISI 304
Strain Hardened
1/4 thr 3/4
Over 3/4 thru 1
Over 1 thru 1-1/4
Over 1-1/4 thru 1-1/2



100,000
80,000
65,000
50,000
125,000
115,000
105,000
100,000

B8C
ASTM A193
Grade B8C
AISI 347
Strain Hardened

B8M
ASTM A193
Grade B8M
AISI 316
Strain Hardened
95,000
80,000
65,000
50,000
110,000
100,000
95,000
90,000

B8T
ASTM A193
Grade B8T
AISI 321
Strain Hardened
100,000
80,000
65,000
50,000
125,000
115,000
105,000
100,000

L7
ASTM A320
Grade L7
Bolts,
Screws,
Studs for Low-Temperature Service
AISI 4140,
4142 or 4145
1/4 thru 2-1/2 105,000 125,000

L7A
ASTM A320
Grade L7A
AISI 4037

L7B
ASTM A320
Grade L7B
AISI 4137

L7C
ASTM A320
Grade LC7
AISI 8740

L43
ASTM A320
Grade L43
AISI 4340 1/4 thru 4 105,000 125,000

B8
ASTM A320
Grade B8
Bolts,
Screws,
Studs for Low-Temperature Service
AISI 304 1/4 and larger 30,000 75,000

B8C
ASTM A320
Grade B8C
AISI 347

B8T
ASTM A320
Grade B8T
AISI 321

B8F
ASTM A320
Grade B8F
AISI 303
or 303Se

B8M
ASTM A320
Grade B8M
AISI 316

B8
ASTM A320
Grade B8
AISI 304 1/4 thru 3/4
Over 3/4 thru 1
Over 1 thru 1-1/4
Over 1-1/4 thru 1-1/2



100,000
80,000
65,00
50,00
100,000
80,000
65,00
50,00

B8C
ASTM A320
Grade B8C
AISI 347

B8F
ASTM A320
Grade B8F
AISI 303
or 303Se

B8M
ASTM A320
Grade B8M
AISI 316

B8T
ASTM A320
Grade B8T
AISI 321
SAE J429
Grade 5
Bolts,
Screws,
Studs
Medium Carbon Steel, Quenched and Tempered 1/4 thru 1
Over 1 to 1-1/2
85,000
74,000
92,000
81,000
120,000
105,000
ASTM A449 1/4 thru 1
Over 1 to 1-1/2
Over 1-1/2 thru 3
85,000
74,000
55,000
92,000
81,000
58,000
120,000
105,000
90,000
SAE J429
Grade 5.1
Sems Low or Medium Carbon Steel, Quenched and Tempered No. 6
thru 3/8
85,000 120,000
SAE J429
Grade 5.2
Bolts,
Screws,
Studs
Low Carbon Martensitic Steel, Quenched and Tempered 1/4 thru 1 85,000 92,000 120,000

A325
ASTM A325
Type 1
High Strength
Structural Bolts
Medium Carbon Steel, Quenched and Tempered 1/2 thru 1
1-1/8 thru 1-1/2
85,000
74,000
92,000
81,000
120,000
105,000

A325
ASTM A325
Type 2
Low Carbon Martensitic Steel, Quenched and Tempered 1/2 thru 1 85,000 92,000 120,000

A325
ASTM A325
Type 3
Atmospheric Corrosion Resisting Steel, Quenched and Tempered 1/2 thru 1
1-1/8 thru 1-1/2
85,000
74,000
92,000
81,000
120,000
105,000

BB
ASTM A354
Grade BB
Bolts,
Studs
Alloy Steel, Quenched and Tempered 1/4 thru 2-1/2
2-3/4 thru 4
80,000
75,000
83,000
78,000
105,000
100,000

BC
ASTM A354
Grade BC
105,000
95,000
109,000
99,000
125,000
115,000
SAE J429
Grade 7
Bolts,
Screws,
Medium Carbon Alloy Steel, Quenched and Tempered 4 1/4 thru 1-1/2 105,000 115,000 133,000
SAE J429
Grade 8
Bolts,
Screws,
Studs
Medium Carbon Alloy Steel, Quenched and Tempered 1/4 thru 1-1/2 120,000 130,000 150,000
ASTM A354
Grade BD
Alloy Steel, Quenched and Tempered 4

No Grade
Mark
SAE J429
Grade 8.1
Studs Medium Carbon Alloy or SAE 1041 Modified Elevated Temperature Drawn Steel 1/4 thru 1-1/2 120,000 130,000 150,000

A490
ASTM A490 High Strength Structural Bolts Alloy Steel, Quenched and Tempered 1/2 thru 1-1/2 120,000 130,000 150,000 min
170,000 max

No Grade
Mark
ISO R898
Class 4.6
Bolts,
Screws,
Studs
Medium Carbon Steel, Quenched and Tempered All Sizes
thru 1-1/2
33,000 36,000 60,000

No Grade
Mark
ISO R898
Class 5.8
55,000 57,000 74,000
8.8

or

88
ISO R898
Class 8.8
Alloy Steel, Quenched and Tempered 85,000 92,000 120,000
10.9

or

109
ISO R898
Class 10.9
120,000 130,000 150,000

Your hex bolt may require a hex nut.

Machinability of Metals

Machinability is the defined as the ease with which a material can be machined. The American Iron and Steel Institute has determined that AISI 1112 Steel has a machinability of 100%. Other materials are compared below:


Carbon Steels

  • 1015 – 72%
  • 1018 – 78%
  • 1020 – 72%
  • 1022 – 78%
  • 1030 – 70%
  • 1040 – 64%
  • 1042 – 64%
  • 1050 – 54%
  • 1095 – 42%
  • 1117 – 91%
  • 1137 – 72%
  • 1141 – 70%
  • 1141 annealed – 81%
  • 1144 – 76%
  • 1144 annealed – 85%
  • 1144 stress-proof – 83%
  • 1212 – 100%
  • 1213 – 136%
  • 12L14 – 170%
  • 1215 – 136%

Alloy Steels

  • 2355 annealed – 70%
  • 4130 annealed – 72%
  • 4140 annealed – 66%
  • 4142 annealed – 66%
  • 41L42 annealed – 77%
  • 4150 annealed – 60%
  • 4340 annealed – 57%
  • 4620 – 66%
  • 4820 annealed – 49%
  • 52100 annealed – 40%
  • 6150 annealed – 60%
  • 8620 – 66%
  • 86L20 – 77%
  • 9310 annealed – 51%

Stainless Steels and Super Alloys

  • 302 annealed – 45%
  • 303 annealed – 78%
  • 304 annealed – 45%
  • 316 annealed – 45%
  • 321 annealed – 36%
  • 347 annealed – 36%
  • 410 annealed – 54%
  • 416 annealed – 110%
  • 420 annealed – 45%
  • 430 annealed – 54%
  • 431 annealed – 45%
  • 440A – 45%
  • 15-5PH condition A – 48%
  • 17-4PH condition A – 48%
  • A286 aged – 33%
  • Hastelloy X – 19%

Tool Steels

  • A-2 – 42%
  • A-6 – 33%
  • D-2 – 27%
  • D-3 – 27%
  • M-2 – 39%
  • O-1 – 42%
  • O-2 – 42%

Gray Cast Iron

  • ASTM class 20 annealed – 73%
  • ASTM class 25 – 55%
  • ASTM class 30 – 48%
  • ASTM class 35 – 48%
  • ASTM class 40 – 48%
  • ASTM class 45 – 36%
  • ASTM class 50 – 36%

Nodular Ductile Iron

  • 60-40-18 annealed – 61%
  • 65-45-12 annealed – 61%
  • 80-55-06 – 39%

Aluminum / Magnesium Alloys

  • aluminum, cold drawn – 360%
  • aluminum, cast – 450%
  • aluminum, die cast – 76%
  • magnesium, cold drawn – 480%
  • magnesium, cast – 480%

Galvanic Corrosion and the Compatibility of Metals – Anodic Index

Designs sometimes cause dissimilar metals to be in contact within an assembly.  Increased variance of the two metals’ anodic index cause accelerated corrosion of the more anodic metal.  This is called galvanic corrosion.  The variance in anodic index can be controlled somewhat through coatings (paint, epoxy, powder coat, etc) and plating (zinc, chrome, etc).

The table below provides a generalize guide for predicting the anodic corrosion two dissimilar metals are prone to.  The service environment also plays a role:

  • For harsh environments: outdoors, high humidity, and salt environments fall into this category. Typically there should be not more than 0.15 V difference in the “Anodic Index”. For example; gold – silver would have a difference of 0.15V being acceptable.
  • For normal environments: storage in warehouses or non-temperature and humidity controlled environments. Typically there should not be more than 0.25 V difference in the “Anodic Index”.
  • For controlled environments: where the temperature and humidity controlled, 0.50 V can be tolerated. Caution should be maintained when deciding for this application as humidity and temperature do vary from regions.

Anodic Index

Metallurgy Index (V)
Gold, solid and plated, Gold-platinum alloy 0.00
Rhodium plated on silver-plated copper 0.05
Silver, solid or plated; monel metal. High nickel-copper alloys 0.15
Nickel, solid or plated, titanium an s alloys, Monel 0.30
Copper, solid or plated; low brasses or bronzes; silver solder; German silvery high copper-nickel alloys; nickel-chromium alloys 0.35
Brass and bronzes 0.40
High brasses and bronzes 0.45
18% chromium type corrosion-resistant steels 0.50
Chromium plated; tin plated; 12% chromium type corrosion-resistant steels 0.60
Tin-plate; tin-lead solder 0.65
Lead, solid or plated; high lead alloys 0.70
Aluminum, wrought alloys of the 2000 Series 0.75
Iron, wrought, gray or malleable, plain carbon and low alloy steels 0.85
Aluminum, wrought alloys other than 2000 Series aluminum, cast alloys of the silicon type 0.90
Aluminum, cast alloys other than silicon type, cadmium, plated and chromate 0.95
Hot-dip-zinc plate; galvanized steel 1.20
Zinc, wrought; zinc-base die-casting alloys; zinc plated 1.25
Magnesium & magnesium-base alloys, cast or wrought 1.75
Beryllium 1.85

Table of Steel Equivalent Grades (EN, SAE/AISI, UNS, DIN, BS, UNI, JIS)

The table below compares steel equivalent grades of materials from various international specifications.  Note that materials compared are the nearest available grade and may have slight variations in actual chemistry.

Comparison of steel grades by chemistry
EN # EN name SAE UNS DIN BS 970 UNI JIS
Carbon steels
1.1141
1.0401
1.0453
C15D
C18D
1018 CK15
C15
C16.8
040A15
080M15
080A15
EN3B
C15
C16
1C15
S15
S15CK
S15C
1.0503
1.1191
1.1193
1.1194
C45 1045 C45
CK45
CF45
CQ45
060A47
080A46
080M46
C45
1C45
C46
C43
S45C
S48C
1.0726
1.0727
35S20
45S20
1140/1146 35S20
45S20
212M40
En8M
1.0715
1.0736
11SMn37 1215 9SMn28
9SMn36
230M07
En1A
CF9SMn28
CF9SMn36
SUM 25
SUM 22
1.0718
1.0737
11SMnPb30
11SMnPb37
12L14 9SMnPb28
9SMnPb36
230M07 Leaded
En1A Leaded
CF9SMnPb29
CF9SMnPb36
SUM 22L
SUM 23L
SUM 24L
Alloy steels
1.7218 4130 25CrMo4
GS-25CrMo4
708A30
CDS110
25CrMo4 (KB)
30CrMo4
SCM 420
SCM 430
SCCrM1
1.7223
1.7225
1.7227
1.3563
42CrMo4 4140/4142 41CrMo4
42CrMo4
42CrMoS4
43CrMo4
708M40
708A42
709M40
En19
En19C
41CrMo4
38CrMo4 (KB)
G40 CrMo4
42CrMo4
SCM 440
SCM 440H
SNB 7
SCM 4M
SCM 4
1.6582
1.6562
34CrNiMo6 4340 34CrNiMo6
40NiCrMo8-4
817M40
En24
35NiCrMo6 (KB)
40NiCrMo7 (KB)
SNCM 447
SNB24-1-5
1.6543
1.6523
20NiCrMo2-2 8620 21NiCrMo22
21NiCrMo2
805A20
805M20
20NiCrMo2 SNCM 200 (H)
Stainless steels
1.4310 X10CrNi18-8 301 S30100
1.4318 X2CrNiN18-7 301LN
1.4305 X8CrNiS18-9 303 S30300 X10CrNiS18-9 202S 21
En58M
X10CrNiS18-09 SUS 303
1.4301 X2CrNi19-11
X2CrNi18-10
304 S30400 X5CrNi18-9
X5CrNi18-10
XCrNi19-9
304S 15
304S 16
304S 18
304S 25
En58E
X5CrNi18-10 SUS 304
SUS 304-CSP
1.4306 X2CrNi19-11 304L S30403 304S 11 SUS304L
1.4311 X2CrNiN18-10 304LN S30453
1.4948 X6CrNi18-11 304H S30409
1.4303 X5CrNi18-12 305 S30500
1.4401
1.4436
X5CrNiMo17-12-2
X5CrNiMo18-14-3
316 S31600 X5CrNiMo17 12 2
X5CrNiMo17 13 3
X5CrNiMo 19 11
X5CrNiMo 18 11
316S 29
316S 31
316S 33
En58J
X5CrNiMo17 12
X5CrNiMo17 13
X8CrNiMo17 13
SUS 316
SUS316TP
1.4404 X2CrNiMo17-12-2 316L S31603 316S 11 SUS316L
1.4406
1.4429
X2CrNiMoN17-12-2
X2CrNiMoN17-13-3
316LN S31653
1.4571 316Ti S31635 X6CrNiMoTi17-12 320S 33
1.4438 X2CrNiMo18-15-4 317L S31703
1.4541 321 S32100 X6CrNiTi18-10 321S 31 SUS321
1.4878 X12CrNiTi18-9 321H S32109
1.4512 X6CrTi12 409 S40900
410 S41000
1.4016 430 S43000 X6Cr17 430S 17 SUS430
440A S44002
1.4112 440B S44003
1.4125 440C S44004
1.4104 440F S44020 X14CrMoS17 SUS430F
1.4539 X1NiCrMoCu25-20-5 904L N08904
1.4547 X1CrNiMoCuN20-18-7 S31254
Tool steels
1.2363 X100CrMoV5 A-2 X100CrMoV51 BA 2 X100CrMoV5-1 KU SKD 12
1.2379 X153CrMoV12 D-2 X153CrMoV12-1 BD 2 X155CrVMo12-1 SKD 11
1.2510 O-1 100MnCrW4 Bo 1 95MnWCr-5 KU

Remember to note that steel equivalent grades may have slight variations in chemistry between specifications.  These are simply the closed grades commonly available in difference national / international specifications.

AISI / SAE STEEL NUMBERING SYSTEM

The AISI / SAE Steel numbering system has some logic to it that will help you identify some key points right away even if you are not familiar with a particular grade.


  • The first two numbers indicate the alloy according the the chart below.
  • The last two numbers indicate the amount of carbon in the alloy, where the digits “10”, for example, represent 0.10% carbon.

Example AISI/SAE 1020

  • the first two digits indicate this is plain carbon steel.
  • the last two digits indicates that the steel contains approximately 0.20% carbon.

Example AISI/SAE 4340

  • the first two digits indicate this is a Nickel-Chromium-Molybdenum alloy steel
  • the last two digits indicate that the steel contains approximately 0.4% carbon
AISI/SAE Steel Numbering System
Carbon steels 10XX Plain carbon, Mn 1.00% max
11XX Resulfurized free machining
12XX Resulfurized/rephosphorized free machining
15XX Plain carbon, Mn 1.00-1.65%
Manganese steel 13XX Mn 1.75%
Nickel steels 23XX Ni 3.50%
25XX Ni 5.00%
Nickel-chromium steels 31XX Ni 1.25%, Cr .65-.80%
32XX Ni 1.75%, Cr 1.07%
33XX Ni 3.50%, Cr 1.50-1.57%
34XX Ni 3.00%, Cr .77%
Molybdenum steels 40XX Mo .20-.25%
44XX Mo .40-.52%
Chromium-molybdenum steels 41XX Cr .50-.95%, Mo .12-.30%
Nickel-chromium-molybdenum steels 43XX Ni 1.82%, Cr .50-.80%, Mo .25%
47XX Ni 1.05%, Cr .45%, Mo .20-.35%
Nickel-molybdenum steels 46XX Ni .85-1.82%, Mo .20-.25%
48XX Ni 3.50%, Mo .25%
Chromium steels 50XX Cr .27-.65%
51XX Cr .80-1.05%
50XXX Cr .50%, C 1.00% min
51XXX Cr 1.02%, C 1.00% min
52XXX Cr 1.45%, C 1.00% min
Chromium-vanadium steels 61XX Cr .60-.95%, V .10-.15%
Tungsten-chromium steels 72XX W 1.75%, Cr .75%
Nickel-chromium-molybdenum steels 81XX Ni .30%, Cr .40%, Mo .12%
86XX Ni .55%, Cr .50%, Mo .20%
87XX Ni .55%, Cr .50%, Mo .25%
88XX Ni .55%, Cr .50%, Mo .35%
Silicon-manganese steels 92XX Si 1.40-2.00%, Mn .65-.85%, Cr 0-.65%
Nickel-chromium-molybdenum steels 93XX Ni 3.25%, Cr 1.20%, Mo .12%
94XX Ni .45%, Cr .40%, Mo .12%
97XX Ni .55%, Cr .20%, Mo .20%
98XX Ni 1.00%, Cr .80%, Mo .25%

Sheet Metal Gauge Chart – Steel, Stainless, Aluminum, Tubing

Damn you, sheet metal gods!  Why did you create such a stupid system where a “gauge” of one type of metal is a different thickness than the same “gauge” of another metal?   The sheet metal gauge chart will help you with your struggle to pick a ‘standard’ size sheet metal whey you are working on a sheet metal design.


All Dimensions in Inches

Gauge # Sheet Steel Strip & Tubing Aluminum Stainless Steel
6/0
5/0
4/0
3/0
2/0
—-
—-
—-
—-
—-
—-
.500
.454
.425
.380
.5800
.5165
.4600
.4096
.3648
.4687
.4375
.4062
.3750
.3437
0
1
2
3
4
5
—-
—-
—-
.2391
.2242
.2092
.340
.300
.284
.259
.238
.220
.3249
.2893
.2576
.2294
.2043
.1819
.3125
.2812
.2656
.2500
.2344
.2187
6
7
8
9
10
11
.1943
.1793
.1644
.1495
.1345
.1196
.203
.180
.165
.148
.134
.120
.1620
.1443
.1285
.1144
.1019
.0907
.2031
.1875
.1719
.1562
.1406
.1250
12
13
14
15
16
17
.1046
.0897
.0747
.0673
.0598
.0538
.109
.095
.083
.072
.065
.058
.0808
.0720
.0641
.0571
.0508
.0453
.1094
.0937
.0781
.0703
.0625
.0562
18
19
20
21
22
23
.0478
.0418
.0359
.0329
.0299
.0269
.049
.042
.035
.032
.028
.025
.0403
.0359
.0320
.0285
.0253
.0226
.0500
.0437
.0375
.0344
.0312
.0281
24
25
26
27
28
29
.0239
.0209
.0179
.0164
.0149
.0135
.022
.020
.018
.016
.014
.013
.0201
.0179
.0159
.0142
.0126
.0113
.0250
.0219
.0187
.0172
.0156
.0141
30
31
32
33
34
35
36
37
38
.0120
.0105
.0097
.0090
.0082
.0075
.0067
.0064
.0060
.012
.010
.009
.008
.007
.005
.004
—-
—-
.0100
.0089
.0080
.0071
.0063
.0056
.0050
.0045
.0040
.0125
.0109
.0102
.0094
.0086
.0078
.0070
.0066
.0062

Remember, mechanical engineers, if you ever serve on a standards or specifications committee, don’t make up stupid rules and specifications just to be different.  Try to make things common so you don’t need extra tools like this sheet metal gauge chart which should be totally unnecessary.

SCHEDULE 40 & 80 – NPS PIPE DIMENSIONS (PVC, CPVC, ABS)

It’s not necessarily the most frequently needed specification, but you might find yourself needing to know the pipe dimensions from time to time.  Things like ID, OD, wall thickness for a given NPT pipe size are not obvious without a table to reference.


Schedule 40 Pipe Dimensions

Nom. Pipe Size (in) O.D. Average I.D. Min. Wall Nom. Wt./Ft. Max. W.P. PSI
1/8″ 0.405 0.249 0.068 0.051 810
1/4″ 0.540 0.344 0.088 0.086 780
3/8″ 0.675 0.473 0.091 0.115 620
1/2″ 0.840 0.602 0.109 0.170 600
3/4″ 1.050 0.804 0.113 0.226 480
1″ 1.315 1.029 0.133 0.333 450
1-1/4″ 1.660 1.360 0.140 0.450 370
1-1/2″ 1.900 1.590 0.145 0.537 330
2″ 2.375 2.047 0.154 0.720 280
2-1/2″ 2.875 2.445 0.203 1.136 300
3″ 3.500 3.042 0.216 1.488 260
3-1/2″ 4.000 3.521 0.226 1.789 240
4″ 4.500 3.998 0.237 2.118 220
5″ 5.563 5.016 0.258 2.874 190
6″ 6.625 6.031 0.280 3.733 180
8″ 8.625 7.942 0.322 5.619 160
10″ 10.750 9.976 0.365 7.966 140
12″ 12.750 11.889 0.406 10.534 130
14″ 14.000 13.073 0.437 12.462 130
16″ 16.000 14.940 0.500 16.286 130
18″ 18.000 16.809 0.562 20.587 130
20″ 20.000 18.743 0.593 24.183 120
24″ 24.000 22.544 0.687 33.652 120

Schedule 80 Dimensions

Nom. Pipe Size (in) O.D. Average I.D. Min. Wall Nom. Wt./Ft. Max. W.P. PSI
1/8″ .405 .195 0.095 0.063 1230
1/4″ .540 .282 0.119 0.105 1130
3/8″ .675 .403 0.126 0.146 920
1/2″ .840 .526 0.147 0.213 850
3/4″ 1.050 .722 0.154 0.289 690
1″ 1.315 .936 0.179 0.424 630
1-1/4″ 1.660 1.255 0.191 0.586 520
1-1/2″ 1.900 1.476 0.200 0.711 470
2″ 2.375 1.913 0.218 0.984 400
2-1/2″ 2.875 2.290 0.276 1.500 420
3″ 3.500 2.864 0.300 2.010 370
3-1/2″ 4.000 3.326 0.318 2.452 350
4″ 4.500 3.786 0.337 2.938 320
5″ 5.563 4.768 0.375 4.078 290
6″ 6.625 5.709 0.432 5.610 280
8″ 8.625 7.565 0.500 8.522 250
10″ 10.750 9.493 0.593 12.635 230
12″ 12.750 11.294 0.687 17.384 230
14″ 14.000 12.410 0.750 20.852 220
16″ 16.000 14.213 0.843 26.810 220
18″ 18.000 16.014 0.937 33.544 220
20″ 20.000 17.814 1.031 41.047 220
24″ 24.000 21.418 1.218 58.233 210

Flat Washer Dimensions (ASME B18.22.1)

How much space do you need for a bolt if you are using a flat washer?  How long do your threads need to be if you are accounting for the thickness of a washer.  Flat washer dimensions are frequently important while working on mechanical designs.  While there are many size options available, here is a table for the most common flat washer dimensions.


Bolt Size A B C Weight In Pounds
Per 100 Pieces
Inside Diameter Outside Diameter Thickness
3/8 7/16 1 0.083 2
1/2 9/16 1-3/8 0.109 4
5/8 11/16 1-3/4 0.134 8
3/4 13/16 2 0.148 11
7/8 15/16 2-1/4 0.165 15
1 1-1/16 2-1/2 0.165 19
1-1/8 1-1/4 2-3/4 0.165 22
1-1/4 1-3/8 3 0.165 26
1-3/8 1-1/2 3-1/4 0.180 33
1-1/2 1-5/8 3-1/2 0.180 38
1-5/8 1-3/4 3-3/4 0.180 43
1-3/4 1-7/8 4 0.180 50
1-7/8 2 4-1/4 0.180 57
2 2-1/8 4-1/2 0.180 63
2-1/4 2-3/8 4-3/4 0.220 83
2-1/2 2-5/8 5 0.238 96
2-3/4 2-7/8 5-1/4 0.259 110
3 3-1/8 5-1/2 0.284 130

Hex Nut Dimensions

There are lots of reasons you need to know hex nut dimensions.  You need to hex nut height to determine the best length of a fastener in a bolted assembly.  You need to know the size of the hex to make sure you have sufficient clearance for the nut itself, the washer and a wrench.


Size Across Flats* Height
Hex Nut Machine Screw Nut Hex Nut Jam Nut Nylock Nut Machine Screw Nut
0 5/32 3/64
1 5/32 3/64
2 3/16 9/64 1/16
3 3/16 9/64 1/16
4 1/4 9/64 3/32
6 5/16 11/64 7/64
8 11/32 15/64 1/8
10 3/8 15/64 1/8
12 7/16 5/16 5/32
1/4 7/16 7/16 7/32 5/32 5/16 3/16
5/16 1/2 9/16 17/64 3/16 11/32 7/32
3/8 9/16 5/8 21/64 7/32 29/64 1/4
7/16 11/16 3/8 1/4 29/64
1/2 3/4 7/16 5/16 19/32
9/16 7/8 31/64 5/16 41/64
5/8 15/16 35/64 3/8 3/4
3/4 1-1/8 41/64 27/64 7/8
7/8 1-5/16 3/4 31/64 63/64
1 1-1/2 55/64 35/64 1-3/64
* This is also the size of wrench to use.

Hex Cap Bolt Dimensions

Hex cap bolt dimensions are trickier than you think.  By default, they are not threaded all the way, so you need to be careful in your design to make sure you are not threading beyond the capability of the bolt itself.

Just as with the standard nut and washer, it it important to consider the geometric constraints of the hex cap bolt to ensure proper function and easier assembly / disassembly.


Hex Bolt Dimensions s
Basic Product Diameter
Full-Size Body Diameter
Width Across Flats
Width Across Corners
Head Height
Thread Length
Thread Length
Max
Min
Max
Min
Up to 6in
Over 6 in
1/4
.26
.237
7/16
.505
0.484
11/64
0.75
1.00
5/16
.324
.298
1/2
.577
0.552
7/32
0.88
1.13
3/8
.388
.360
9/16
.650
0.62
1/4
1.00
1.25
7/16
.452
.421
5/8
.722
0.687
19/64
1.13
1.38
1/2
.515
.482
3/4
.866
0.826
11/32
1.25
1.50
5/8
.642
.605
15/16
1.083
1.033
27/64
1.50
1.75
3/4
.768
.729
1-1/8
1.299
1.24
1/2
1.75
2.00
7/8
.895
.852
1-5/16
1.516
1.447
37/64
2.00
2.25
1
1.022
.976
1-1/2
1.732
1.653
43/64
2.25
2.50
1-1/8
1.149
1.098
1-11/16
1.949
1.859
3/4
2.50
2.75
1-1/4
1.277
1.223
1-7/8
2.165
2.066
27/32
2.75
3.00
1-3/8
1.404
1.345
2-1/16
2.382
2.273
29/32
3.00
3.25
1-1/2
1.531
1.47
2-1/4
2.598
2.48
1
3.25
3.50
1-3/4
1.785
1.716
2-5/8
3.031
2.893
1-5/32
3.75
4.00
2
2.039
1.964
3
3.464
3.306
1-11/32
4.25
4.50
2-1/4
2.305
2.214
3-3/8
3.897
3.719
1-1/2
4.75
5.00
2-1/2
2.559
2.461
3-3/4
4.33
4.133
1-21/32
5.25
5.5
2-3/4
2.827
2.711
4-1/8
4.763
4.546
1-13/16
5.75
6.00
3
3.081
2.961
4-1/2
5.196
4.959
2
6.25
6.50
3-1/4
3.335
3.21
4-7/8
5.629
5.372
2-3/16
6.75
7.00
3-1/2
3.589
3.461
5-1/4
6.062
5.786
2-5/16
7.25
7.50
3-3/4
3.858
3.726
5-5/8
6.495
6.198
2-1/2
7.75
8.00
4
4.111
3.975
6
6.928
6.612
2-11/16
8.25
8.50