What does TF mean for bolts?

What does TF mean for bolts?

fully tensioned
After (S) comes (TB) and (TF) – both of these represent “fully tensioned” bolts.

What does 8.8 s mean?

Category 8.8/S refers to any bolt of Property Class 8.8, tightened using a standard wrench to a ‘snug- tight’ condition in the same way as for category 4.6/S. Essentially, these bolts are used as higher grade commercial bolts in order to increase the capacity of certain connection types.

What is snug-tight torque?

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.

What are 8.8 s bolts?

Grade 8.8 Bolts belong to the DIN 933 grade 8.8 standard. This is a structural grade for bolts. This is a medium carbon steel bolt specification. These bolts are heat treated by quenched and tempered methods.

What is HC screw?

Varianta HC Special screw The special thread design of the Varianta HC cuts into the top layer over a wide area, ensuring that the screw is securely anchored in the top layer. The Varianta HC can be used independently of the thickness of the lightweight panel, and is used like a conventional chipboard screw.

What is slip-critical bolt?

Slip-critical joint, from structural engineering, is a type of bolted structural steel connection which relies on friction between the two connected elements rather than bolt shear or bolt bearing to join two structural elements.

What is turn of the nut method for tightening bolts?

Turn-Of-Nut is performed by rotating the nut or bolt of a fastener assembly a specific turn angle based on the fastener’s length, and diameter while restraining the unturned element from rotating.

Can you tension a snug bolt?

Prior to final tensioning of structural bolts the steel plies must be brought into effective contact. This is re- ferred to as Snug-tight. i.e. no gap between the steel plates. Snug-tight can be achieved by a few impacts of an impact wrench or by the full effort of a person using a standard podger spanner.

What is fully tensioned bolt?

The bolt will turn further than that – when it is turned to a non-zero setting on the torque wrench, it is a tensioned bolt. When it is tensioned to the enginerring spec, then it is “fully tensioned”. Above or below the spec then it is over or under tensioned respectively.