A stress control bolt (TC bolt) is a sturdy bolt used in steel frame building and construction. The head is typically domed and is not created to be driven. Completion 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 up.
Portland Bolt operates its hot-dip galvanizing tank at 840 Fahrenheit. Is this enough heat to potentially alter the strength of a quenched and tempered fastener? In theory, the amount of heat that a high strength fastener is exposed to during the hot-dip galvanizing process must not modify its mechanical homes. A490 Tension Control Bolts.
The question is, how much heat is required to potentially alter the mechanical residential or commercial properties? On page 4-4 of the Ninth Edition of the AISC Manual (American Institute of Steel Building), the following statement takes place: "Anchor bolt material that is satiated and tempered (heat dealt with) ought to not be bonded or heated." Nevertheless, it does not deal with the quantity of heat that need to be prevented.
Another recommendation that attends to the heating of high strength bolts (which takes place during hot-dip galvanizing) can be found in the ASTM F1554 specification. Area 6. 5.3 of the ASTM F1554 requirements states: "The maximum hot flexing temperature level for heat treated anchor bolts will be less than. 1000F for grade 105.
However, galvanized bolts just stay in the zinc tank for a couple of minutes and despite the fact that the surface area temperature might approach 840, it is unlikely that the whole fastener is heated to that temperature. The most relevant reference discovered in any ASTM requirements addressing the possibility of the hot-dip galvanizing procedure altering the mechanical homes of a high strength fastener is found in area 7.
2 of the new hot-dip galvanizing specification ASTM F2329 which states: "Testing for mechanical properties is not required if the galvanizing procedure is performed at a lower temperature than the tension relief or tempering temperature level of the fasteners. Tension control bolts." This implies that the mechanical residential or commercial properties have the potential to be changed just if high strength bolts are tempered at temperature levels at or below the 840 temperature that the bolts are subjected to during hot-dip galvanizing.
For that reason, it is not possible for the galvanizing temperatures to go beyond the tempering temperature level for these specifications. Although in theory it is possible for the other specs to be tempered below the galvanizing temperature, recent records show that the minimum tempering temperature level utilized for any of these grades noted in Table 2 that Portland Bolt has actually produced is 950.
Tension control bolts are quick, easy and safe to set up. TCB setup is the most affordable cost approach for correctly installing High Strength Friction Grip (HSFG) or Preloaded bolts.
If two washers are being used make sure the washer under the bolt head is put with the chamfered side dealing with the bolt head. Using the electrical shear wrench, engage the inner socket over the bolt spline and the outer socket over the nut (Fig 2). Make sure that both inner and external sockets are fully engaged prior to continuing.