Technical Information for selecting the right tool

	Items	Tension-Nut	Hydraulic Wrench	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
Cost	Maintence cost	Almost zero	Expensive	Expensive

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.