Which Torque Wrench

[Juank]

Which torque wrench for all scuba torque needs. Say Regs and cylinder valves. Which one is the most cost effective?

Thanks

 

[nimoh]

I use a Craftsman micro torque wrench

Craftsman Torque Micro-Clicker Wrench: Get Multiple Jobs Done at Sears

whatever you get, it is important that its range is not too high as they get less accurate when you approach the upper and lower ranges. I would actually prefer to have a torque wrench with a lower range (the one I use is 25-250 inch pounds) as I commonly have it set for 40 inch pounds for most things.

 

[Juank]

Thanks, I will go for it.

 

[Jim Lapenta]

I use the same. I like the 250 inch pound upper limit as turret bolts require 175 and DIN connections 120.

 

[nimoh]

I use the same. I like the 250 inch pound upper limit as turret bolts require 175 and DIN connections 120.

yeah, what Jim said.

I may not have been clear, but I meant I would like to have one with a lower range in addition to the one I already have

 

[underH2Oman]

I have one with the same range.

 

[knotical]

You might want to first check out the specs for the equipment you are most likely to service. For me that ranges from 15 inch-pounds (some regs) to 30 foot-pounds (some valves), and I think those numbers are not unusual. I’m unaware of a reasonably-priced wrench that spans that range with much hope of accuracy, so I use two.

Having said that, many techs seem to get by without ever using a torque wrench.

 

[elan]

I do not think you can get one for all. For the regs I use a 300inch/lb for some valves you need a bit more than that

 

[captain]

Having worked as a mechanic all my life I both with and without using torque wrenches I feel they are most needed in situation of multiple fasteners on a single assembly such as an engine cylinder head. or wheel. If I use a wrench sized for the fastener and don't pull to the point of straining most times I will be within the torque specification. A 6" long wrench on a 3/8" hose fitting will get you in the ball park, With a 12" wrench it will be too tight. Adjustable wrenches generally won't work because a big wrench can be adjusted to fit a small fastener. Stick with a set of combination wrenches sized to the size fastener. Get the feel by comparing the difference between using a torque wrench and a regular wrench on the same fastener.
The problem with torque wrenches is you need special crow foot wrenches if you can't use a socket on the fastener such as a hose. More failures happen because of over tightening a fastener than under tightening one.
A good beam type torque wrench never need recalibration and is the most accurate. I don't particularly trust cheap micrometer type pull until they click wrenches and even the good ones need to be checked for accuracy regularly.
Scuba manufactures specify torque wrenches more to keep shop gorillas from over tightening and stressing fasteners to the point of possible failure then the possibility of something coming loose.
Turret bolts are a prime example, if it is a sudden failure of the turret bolt it was over stressed because someone was afraid of it getting loose.

 

[nimoh]

Having worked as a mechanic all my life I both with and without using torque wrenches I feel they are most needed in situation of multiple fasteners on a single assembly such as an engine cylinder head. or wheel. If I use a wrench sized for the fastener and don't pull to the point of straining most times I will be within the torque specification. A 6" long wrench on a 3/8" hose fitting will get you in the ball park, With a 12" wrench it will be too tight. Adjustable wrenches generally won't work because a big wrench can be adjusted to fit a small fastener. Stick with a set of combination wrenches sized to the size fastener. Get the feel by comparing the difference between using a torque wrench and a regular wrench on the same fastener.
The problem with torque wrenches is you need special crow foot wrenches if you can't use a socket on the fastener such as a hose. More failures happen because of over tightening a fastener than under tightening one.
A good beam type torque wrench never need recalibration and is the most accurate. I don't particularly trust cheap micrometer type pull until they click wrenches and even the good ones need to be checked for accuracy regularly.
Scuba manufactures specify torque wrenches more to keep shop gorillas from over tightening and stressing fasteners to the point of possible failure then the possibility of something coming loose.
Turret bolts are a prime example, if it is a sudden failure of the turret bolt it was over stressed because someone was afraid of it getting loose.

I use crow foot wrenches on hoses. There is a simple formula (that should be included in your torque wrench manual) to adjust for extending the length. On a regulator hose, I torque to 40 inch pounds and set my wrench to 36 inch pounds.

It seems to me that you are arguing that using standard wrenches and getting a feel for the pressure applied will get you in the ballpark, and is preferable to over-tightening with a torque wrench by 4 inch pounds.

Here is the formula, in case anyone is interested: