Us Bolts Tensile Proof Load

Reference data and engineering information about us bolts tensile proof load for mechanics applications.

boltstensileproofloadCalculator

Overview

Engineering reference data for Us Bolts Tensile Proof Load in mechanics.

Key Formulas

Newton's Second Law

$F = ma$

Force = mass × acceleration.

Work

$W = Fd\cos\theta$

Work = force × displacement × cos(angle).

Kinetic Energy

$E_k = \frac{1}{2}mv^2$

Energy of motion.

Potential Energy

$E_p = mgh$

Gravitational potential energy.

Variables

Symbol	Description	Unit
$F$	Force	N
$m$	Mass	kg
$a$	Acceleration	m/s²
$v$	Velocity	m/s

Material Grades and Properties

Grade	Material	Proof Load (psi)	Minimum Tensile Strength (psi)
Grade 2	Low Carbon Steel	55,000 (up to 3/4") / 33,000 (3/4"–1-1/2")	74,000 / 66,000
Grade 5	Medium Carbon Steel, Quenched & Tempered	85,000 (up to 1") / 74,000 (1"–1-1/2")	105,000
Grade 8	Medium Carbon Alloy Steel, Quenched & Tempered	120,000 (up to 1-1/2")	150,000
Lamalloy	Medium Carbon Alloy Steel, Quenched & Tempered	145,000 (up to 1-1/2")	180,000

Clamp load is typically specified as 75% of proof load to provide a safety margin against bolt yielding while maintaining joint integrity.

U.S. Bolts - Coarse Threads Proof Loads

14 rows

U.S. Bolts Coarse Threads – Proof Loads (lbf)
Nom Bolt Size(in)	Grade 2(lbf)	Grade 5(lbf)	Grade 8(lbf)	Lamalloy(lbf)
1/4	1750	2700	3800	4600
5/16	2900	4450	6300	7600
3/8	4250	6600	9300	11250
7/16	5850	9050	12800	15400
1/2	7800	12100	17000	20600
9/16	10000	15500	21800	26400
5/8	12400	19200	27100	32750
3/4	18400	28400	40100	48500
7/8	15200	39300	55400	67000
1	20000	51500	72700	87900
1-1/8	25200	56500	91600	110700
1-1/4	32000	71700	116300	140500
1-3/8	38100	85500	138600	167500
1-1/2	46400	104000	168600	203700

Source: engineeringtoolbox.com

U.S. Bolts - Coarse Threads Clamp Loads

14 rows

U.S. Bolts Coarse Threads – Clamp Loads (lbf). Clamp load = 75% of proof load.
Nom Bolt Size(in)	Grade 2(lbf)	Grade 5(lbf)	Grade 8(lbf)	Lamalloy(lbf)
1/4	1313	2025	2850	3450
5/16	2175	3338	4725	5700
3/8	3188	4950	6975	8438
7/16	4388	6788	9600	11550
1/2	5850	9075	12750	15450
9/16	7500	11625	16350	19800
5/8	9300	14400	20325	24563
3/4	13800	21300	30075	36375
7/8	11400	29475	41550	50250
1	15000	38625	54525	65925
1-1/8	18900	42375	68700	83025
1-1/4	24000	53775	87225	105375
1-3/8	28575	64125	103950	125625
1-1/2	34800	78000	126450	152775

Source: engineeringtoolbox.com

U.S. Bolts - Fine Threads Proof Loads

14 rows

U.S. Bolts Fine Threads – Proof Loads (lbf)
Nom Bolt Size(in)	Grade 2(lbf)	Grade 5(lbf)	Grade 8(lbf)	Lamalloy(lbf)
1/4	2000	3100	4350	5280
5/16	3200	4900	6950	8410
3/8	4800	7450	10500	12730
7/16	6550	10100	14200	17200
1/2	8800	13600	19200	23200
9/16	11200	17300	24400	29450
5/8	14100	21800	30700	37100
3/4	20500	31700	44800	54100
7/8	16800	43300	61100	73800
1	21900	56400	79600	96200
1-1/8	28200	63350	102700	124100
1-1/4	35400	79400	128800	155600
1-3/8	43400	97300	157800	190700
1-1/2	52200	117000	189700	229200

Source: engineeringtoolbox.com

U.S. Bolts - Fine Threads Clamp Loads

Interactive Charts

US Bolts Coarse Threads - Proof Loads

Bolt Stretching and Tensile Stress

ISO 724 - Metric Threads

References

Original Source

Source: engineeringtoolbox.com