Bolt Engineer(c)

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Technical Information for selecting the right tool

Hydraulic Wrench
Hydraulic Wrench
Hydraulic Bolt-tensioner
Hydraulic Bolt-tensioner
Purpose of Use Tension-Ccontrole Good Not recommended Best
Torque-controle Not-good Best Not-good
Measuring & Testing Tension-measuring device Torque-test-bench Tension-measuring device
For Explosion Proof Perfect Air-pump needed Air-pump or or handpump needed
Power Supply Not-needed Needed Not-needed by handpump
Operation When tightening the bolts so many as 10 pcs or more of M36 for Example Not recommended Best Not bad
Bolts so less as 5 pcs or less with M52 for example Best Inconvenient Inconvenient
Prepration for tightening Ony hand torque-wrench anywhere Electric or pneumatic pump, tool & hoses needed Same as the left
Necessity of Reaction part Not-needed Needed Not-needed
Trouble Trouble free Risk of oil-leakage Same as the left
For Retightening Only hand torque-wrench Electric power-pump, tool & hoses Same as the left
Operation at Ultra-narrow spaces Best Not easy Same as the left
Weight for tightening M56 as example No weight Total 30kg approx. Total 25kg approx.
Performance Variation of Bolt tension Minimum Very large Minimum
Friction between the thread-surfaces & nut seat-surfaces Zero Very large Zero
Tightening Performance for bolts in short length like bolt-dia x 3 or less for example Best Best Not recommended
Tightening performance for bolts in long length like bolt-dia x 5 or more for example Good Good Best
Against Vibration No loosening Loosenig happens Loosenig happens
Cost Price Cheapest Expensive Less expensive
Maintence cost Almost zero Expensive Expensive
Conclusion !

When the bolt quantity is less than 5 pcs and in large sizes, Tension-Nut is most recommended, in the senses of easy-operation/safety in working/speedy tightening-time & economical cost.