What does TC mean on bolt?

tension control bolt
A tension control bolt (TC bolt) is a heavy duty bolt used in steel frame construction. The head is usually domed and is not designed to be driven. The end of the shank has a spline on it which is engaged by a special power wrench which prevents the bolt from turning while the nut is tightened.

What nut goes with A490?

A490 Recommended Hardware

Nuts Washers
Type 1 Type 1
A563DH F436-1
Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A490 heavy hex structural bolts. Follow the link for an ASTM A563 Nut Compatibility Chart.

Can A490 bolts be galvanized?

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.

Are TC bolts galvanized?

Tension control bolts are available in one of two different types: ASTM: A325 tension control bolts (F1852), in plain or mechanically galvanized, and ASTM: A490 bolts (F2280), which are plain and not available with a coating.

What are TC bolts used for?

Tension Control Bolts also known as tc bolts are used for high strength, steel to steel fastening. It is one of the most commonly used fasteners for high strength applications, even preferred over large hex bolts. The head is dome-shaped and is not designed to be driven with normal tools.

What is the difference between A325 and A490 bolts?

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. In addition to the requirements of the RC test, if the bolt tensions are outside of the specified limits the fasteners shall be rejected.

What grade are A490 bolts?

Type 3 grade
Type 3 grade A490 bolts shall be marked “A490”.

What is the difference between A325 and Grade 8 bolts?

A325 bolts are typically manufactured from a medium carbon steel (although they can be made from an alloy) while SAE grade 8 bolts are made from a medium carbon alloy steel. Grade 8 bolts are significantly stronger than an A325. An ASTM specification with similar strength properties to grade 8 is ASTM A490.

Where are TC bolts used?

Is A490 stronger than A325?

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.

What is the tensile strength of ASTM A490 bolts?

Type 3 A325 bolts shall be marked “A325” to distinguish them from standard A325s. ASTM A490 bolts are available in diameters from ½ to 1-1/2 inch diameters with a minimum tensile strength of 150,000 PSI for all diameters, and are offered in two types.

How big is an ASTM A490 imperial head?

Imperial head markings and mechanical properties Specification Nominal size range [in] ASTM A490 Type 1 1⁄2 –1- 1⁄2 ASTM A490 Type 2 (withdrawn) 1⁄2 –1 ASTM A490 Type 3 1⁄2 –1- 1⁄2

Can a galvanized A490 bolt be electroplated?

Type 3 A490 bolts shall be marked “A490”. ASTM A490 bolts should not be galvanized or electroplated. The problem with hot dip galvanizing is that the molten bath of zinc exceeds the fastener’s tempering temperature and would cause the fastener to anneal in the bath.

What’s the difference between ASTM A490 and A325?

In 2016, specifications A325 and A490 were officially withdrawn by ASTM and replaced by ASTM F3125. A325 and A490 heavy hex structural bolts are now grades under the new F3125 specification. There are also three connection types defined: SC: A slip critical connection. N: A bearing type connection where the threads are on the shear plane.