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Metal Reference Tools

Gauge charts, hardness conversion, fraction-decimal tables, temper codes, melting points, and mill tolerances — everything you need in one place.

Gauge / Thickness Conversion

Stainless steel uses MSG (Manufacturers’ Standard Gauge) per ASTM A480. Aluminum uses Brown & Sharpe (B&S) gauge. Lower gauge = thicker material.

Stainless Steel — MSG Gauge

GaugeInchesmm
7 ga0.1793"4.55
8 ga0.1644"4.18
9 ga0.1495"3.80
10 ga0.1345"3.42
11 ga0.1196"3.04
12 ga0.1046"2.66
13 ga0.0897"2.28
14 ga0.0747"1.90
15 ga0.0673"1.71
16 ga0.0598"1.52
17 ga0.0538"1.37
18 ga0.0478"1.21
19 ga0.0418"1.06
20 ga0.0359"0.91
21 ga0.0329"0.84
22 ga0.0299"0.76
23 ga0.0269"0.68
24 ga0.0239"0.61
25 ga0.0209"0.53
26 ga0.0179"0.45
27 ga0.0164"0.42
28 ga0.0149"0.38
29 ga0.0135"0.34
30 ga0.0120"0.30
31 ga0.0105"0.27
32 ga0.0097"0.25
33 ga0.0090"0.23
34 ga0.0082"0.21
35 ga0.0075"0.19
36 ga0.0067"0.17
37 ga0.0064"0.16
38 ga0.0060"0.15

Aluminum — Brown & Sharpe Gauge

GaugeInchesmm
1 ga0.2893"7.35
2 ga0.2576"6.54
3 ga0.2294"5.83
4 ga0.2043"5.19
5 ga0.1819"4.62
6 ga0.1620"4.12
7 ga0.1443"3.67
8 ga0.1285"3.26
9 ga0.1144"2.91
10 ga0.1019"2.59
11 ga0.0907"2.30
12 ga0.0808"2.05
14 ga0.0641"1.63
16 ga0.0508"1.29
18 ga0.0403"1.02
20 ga0.0320"0.81
22 ga0.0253"0.64
24 ga0.0201"0.51
26 ga0.0159"0.40
28 ga0.0126"0.32
30 ga0.0100"0.25

Hardness Conversion Table

Approximate equivalents per ASTM E140. Rockwell C for hardened steels, Rockwell B for softer metals (aluminum, brass, mild steel).

Rockwell C (HRC)Rockwell B (HRB)Brinell (HB)Vickers (HV)
65—739832
60—627697
55—545595
50—481513
45—421446
40—371392
35—331350
30—286302
25—253266
20—228238
—100240251
—95207218
—90183192
—85163171
—80146153
—75131137
—70118124
—65107112
—6097102

Fraction / Decimal / Millimeter Equivalents

All 64ths of an inch with decimal and metric equivalents.

FractionDecimal (in)mm
1/64"0.01560.397
1/32"0.03130.794
3/64"0.04691.191
1/16"0.06251.588
5/64"0.07811.984
3/32"0.09382.381
7/64"0.10942.778
1/8"0.12503.175
9/64"0.14063.572
5/32"0.15633.969
11/64"0.17194.366
3/16"0.18754.763
13/64"0.20315.159
7/32"0.21885.556
15/64"0.23445.953
1/4"0.25006.350
17/64"0.26566.747
9/32"0.28137.144
19/64"0.29697.541
5/16"0.31257.938
21/64"0.32818.334
11/32"0.34388.731
23/64"0.35949.128
3/8"0.37509.525
25/64"0.39069.922
13/32"0.406310.319
27/64"0.421910.716
7/16"0.437511.113
29/64"0.453111.509
15/32"0.468811.906
31/64"0.484412.303
1/2"0.500012.700
FractionDecimal (in)mm
33/64"0.515613.097
17/32"0.531313.494
35/64"0.546913.891
9/16"0.562514.288
37/64"0.578114.684
19/32"0.593815.081
39/64"0.609415.478
5/8"0.625015.875
41/64"0.640616.272
21/32"0.656316.669
43/64"0.671917.066
11/16"0.687517.463
45/64"0.703117.859
23/32"0.718818.256
47/64"0.734418.653
3/4"0.750019.050
49/64"0.765619.447
25/32"0.781319.844
51/64"0.796920.241
13/16"0.812520.638
53/64"0.828121.034
27/32"0.843821.431
55/64"0.859421.828
7/8"0.875022.225
57/64"0.890622.622
29/32"0.906323.019
59/64"0.921923.416
15/16"0.937523.813
61/64"0.953124.209
31/32"0.968824.606
63/64"0.984425.003
1"1.000025.400

Temper Designation Guide

What temper codes mean and when to use each. T6 is the most common structural temper. H tempers are strain-hardened (cold worked). O is annealed (softest, most formable).

Aluminum

H12Strain-Hardened, 1/4 Hard

Cold worked to 1/4 hard. Moderate strength increase over annealed.

H14Strain-Hardened, 1/2 Hard

Cold worked to 1/2 hard. Good balance of strength and formability.

H16Strain-Hardened, 3/4 Hard

Cold worked to 3/4 hard. Higher strength, reduced ductility.

H18Strain-Hardened, Full Hard

Maximum cold work without annealing. Highest strength in H tempers.

H32Strain-Hardened & Stabilized, 1/4 Hard

Cold worked then thermally stabilized. Slightly lower strength than H12 but more stable properties.

H34Strain-Hardened & Stabilized, 1/2 Hard

Cold worked then stabilized. Common for 5xxx marine alloys.

H36Strain-Hardened & Stabilized, 3/4 Hard

Cold worked then stabilized to 3/4 hard.

H38Strain-Hardened & Stabilized, Full Hard

Maximum cold work with thermal stabilization.

H111Annealed & Slightly Strain-Hardened

Annealed and given a small amount of strain hardening during fabrication.

H116Strain-Hardened for Marine

Special temper for 5xxx alloys requiring resistance to exfoliation corrosion. Standard for marine hull structures.

T3Solution Treated & Cold Worked

Solution heat treated, cold worked, then naturally aged. Used for high-damage-tolerance applications.

T351Solution Treated, Stress Relieved, Naturally Aged

T3 with stress relief by stretching. Standard for 2024 plate and bar.

T4Solution Treated & Naturally Aged

Solution heat treated then naturally aged to a stable condition. Good formability.

T5Artificially Aged Only

Cooled from hot working then artificially aged. Common for 6063 architectural extrusions.

T6Solution Treated & Artificially Aged

Full heat treatment for maximum strength. The most common heat-treated temper for structural aluminum.

T651T6 + Stress Relieved by Stretching

T6 properties with stress relief. Standard for 6061 and 7075 plate. Better dimensional stability during machining.

T7Solution Treated & Overaged

Intentionally overaged beyond peak strength for improved stress corrosion cracking resistance.

T7451T74 + Stress Relieved

Overaged for SCC resistance with stress relief. Standard for 7050 thick sections.

OAnnealed

Fully annealed to lowest strength and maximum ductility. Best formability for deep drawing and bending.

FAs-Fabricated

No special control over thermal or strain-hardening conditions. Properties are not guaranteed.

Stainless Steel

2BCold Rolled, Annealed, Pickled

Standard mill finish for stainless sheet. Smooth, slightly reflective. The baseline finish for most applications.

#4Brushed / Satin

Polished with 120-150 grit abrasive. Directional satin finish. Standard for architectural and food service.

#8Mirror

Mirror-polished to a highly reflective finish. Used for decorative panels, mirrors, and signage.

HRAPHot Rolled, Annealed, Pickled

Hot rolled mill finish. Rougher than 2B. Used for plate and structural applications where appearance is not critical.

Brass & Copper

H02Half Hard

Cold worked to half-hard condition. Increased strength while retaining some formability.

H04Hard

Cold worked to hard condition. Higher strength, limited bending capability.

H08Spring

Cold worked to spring temper. Highest strength for spring and connector applications.

Melting Point Reference

Solidus to liquidus range by alloy. Aluminum alloys melt 890–1,215°F. Stainless: 2,500–2,650°F.

AlloyMetalMelting Range (°F)Melting Range (°C)
6061Aluminum1,080 - 1,205°F582 - 652°C
6063Aluminum1,140 - 1,210°F616 - 654°C
7075Aluminum890 - 1,175°F477 - 635°C
5052Aluminum1,125 - 1,200°F607 - 649°C
3003Aluminum1,190 - 1,210°F643 - 654°C
2024Aluminum935 - 1,180°F502 - 638°C
1100Aluminum1,190 - 1,215°F643 - 657°C
304Stainless Steel2,550 - 2,650°F1,399 - 1,454°C
316Stainless Steel2,500 - 2,550°F1,371 - 1,399°C
303Stainless Steel2,550 - 2,590°F1,399 - 1,421°C
360Brass1,630 - 1,650°F888 - 899°C
260Brass1,680 - 1,750°F916 - 954°C
110Copper1,949 - 1,981°F1,065 - 1,083°C
122Copper1,945 - 1,975°F1,063 - 1,079°C

Standard Mill Tolerances

Typical tolerances for aluminum per ASTM B209 / AMS-QQ-A-250. Stainless steel and other metals may differ. Always confirm tolerances with your supplier for critical applications.

DimensionSheetPlateRound BarRound TubeSquare BarAngle
Thickness±0.003" to ±0.010"±0.010" to ±0.045"N/A±10% of wallN/A±0.008" to ±0.012"
Width±0.062" to ±0.125"±0.125" to ±0.500"N/AN/AN/A±0.024" to ±0.062"
Diameter / SizeN/AN/A±0.002" to ±0.010"±0.005" OD±0.008" to ±0.012"N/A
Length+0.250" / -0"+0.500" / -0"+0.125" / -0"+0.125" / -0"+0.125" / -0"+0.125" / -0"
Straightness (per ft)N/AN/A0.012" per ft0.025" per ft0.012" per ft0.025" per ft

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