What is the torque requirement for bolt tightening?

ASTM A449 / SAE Grade 5*

Bolt Size	TPI	Tightening Torque (ft lbs)
Galv+Waxed
1⁄2	13	38
9⁄16	12	54
5⁄8	11	75

What nuts go with A490 bolts?

A490 Recommended Hardware Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A490 heavy hex structural bolts.

What grade is an A490 bolt?

F3125 Grade A490 Bolts Grade A490 bolts can be made of Type 1 higher carbon alloy steel or Type 3 weathering steel. Unlike Grade A325, Grade A490 bolts cannot be galvanized.

What is the difference between A325 and A490 bolts?

A490 bolts are more susceptible to brittle fracture than A325 bolts which are 120/105 minimum tensile strength steel. To minimize the risk of brittle fracture A490 bolts have both a minimum and a maximum tensile strength specified. FHWA recommends that A325 bolts be used wherever possible.

What is recommended torque?

US Recommended Bolt Torque

Size	Recommended Torque
Grade 2	18-8 S/S
1/4″	4	7.8
5/16″	8	11.8
3/8″	15	22

Can you galvanized A490 bolts?

A490 covers heavy hex structural bolts (tensile strength of 150 to 173 ksi) and currently, ASTM Standards do not allow hot-dip galvanizing of A490 bolts for corrosion protection. Citing a concern of hydrogen embrittlement, A490 only allows a type of zinc/aluminum coating to be used on high-strength bolts.

Can you use Grade 5 nuts on Grade 8 bolts?

With Grade 5, A325 and metric 8.8 bolts, low strength nuts can be safely used unless the code prohibits them. With the stronger Grade 8, A490 and metric 10.9, high strength nuts have to be used and these bolts can strip the threads out of mild steel nuts.

Can A490 bolts be galvanized?

What is SAE Grade 8?

8. This grade is part of the SAE classification; it is the minimum standard of the automotive and structural industries, plus it is used in high-temperature applications. Grade 8 is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.

Do structural bolts require washers?

It is known that the required grade of washer to be used with an A325 or A490 structural bolt is an ASTM F436 hardened washer, however whether or not a washer is required to be used in a given application is often brought into question.

How do I calculate torque?

A practical way to calculate the magnitude of the torque is to first determine the lever arm and then multiply it times the applied force. The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. and the magnitude of the torque is τ = N m.

What is the torque for a 12mm bolt?

Metric Recommended Bolt Torque

Bolt Diameter (mm)	Recommended Torque (Nm)
Class 8.8	Class 10.9
10	55	75
12	100	135
14	160	215

Why is hot dip galvanized not allowed for A490 bolts?

Can Grade 5 bolts be hot dipped galvanized?

Plain finish SAE J995 Grade 5 nuts can be run through a galvanizing line, but the nuts will then need to be tapped oversize to accommodate the thickness of the zinc on the threads of the bolts which is both labor-intensive and expensive.

What is a snug tight condition?

Snug-tight is the condition that exists when all of the plies in a connection have been pulled into firm contact by the bolts in the joint and all of the bolts in the joint have been tightened sufficiently to prevent the removal of the nuts without the use of a wrench.

Should I use Grade 5 or Grade 8 bolts?

Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions. Grade 8 bolts have 6 evenly spaced radial lines on the head.

What is the torque range of a A490?

TORQUE ASTM A490 Bolt Size TPI Tension (lbs) MIN Tension (lbs) MAX Tightening Torque Range (ft lbs) (Min-Ma 1/2″ 13 15,000 18,000 125 – 150 5/8″ 11 24,000 29,000 250 – 302 3/4″ 10 35,000 42,000 438 – 525 7/8″ 9 49,000 59,000 715 – 860

What are ASTM A490 bolts?

ASTM A490 Bolts are intended for used in structural connections similar to ASTM A325/A325M but being produced from alloy steel instead of medium carbon steel, possed high tensile strength. There are two versions of this specification; ASTM A490 covering imperial sized high tensile bolting and A490M for metric sized bolts.

How do you determine the correct torque?

Because there are many variables that affect the torque-tension relationship, the only way to determine the correct torque is through experimentation under actual joint and assembly conditions.