What is the sequence for tightening head bolts?

What is the sequence for tightening head bolts?

Normally you would tighten conventional head bolts in a crisscross pattern in three steps, to one-third, two-thirds, and then to the final torque. Stretch bolts are tightened in a torque-plus-angle sequence. Various engines use similar but different sequences and specification.

What is the tightening sequence?

What is a Bolt Tightening sequence. Bolt tightening sequences are when an arrange of bolts are tightened in a pattern to the required torque. The sequence the bolts are tightened is a symmetrical pattern to reduce the amount of pre-load lost in a bolt, as a result of elastic interactions.

What is bolt sequence?

Bolt tightening sequences are when an arrange of bolts are tightened in a pattern to the required torque. The sequence the bolts are tightened is a symmetrical pattern to reduce the amount of pre-load lost in a bolt, as a result of elastic interactions. Torque is normally applied to a bolt using a torque wrench.

How are bolts numbered when using a star pattern?

Before they are tightened, bolts can be numbered sequentially (1,2,3,4 etc) in a clockwise direction around the flange (fig 1 below). Or they can be numbered by the order of tightening (fig 2 below).

What’s the torque sequence?

Bolt tightening sequence or torque sequence is defined in the torque tightening procedure. Most company has their Flange bolt torque tightening procedure that used during construction and operation of the plant. Flange joints are torque tight with the help of a torque wrench (Manual or hydronic wrench).

Should you use blue Loctite on head bolts?

NO! You can use blue locktite in alot of places, but your headbolts are not one of them. Headbolts need to be brought up to torque specs in stages, and in a specific order (see a motor manual), and then re-torqued after the engine has been run for awhile to make sure they are all at the proper torque value.

  • October 14, 2022