Good in/lb torque wrench/screwdriver?
- Thread starter mattri
- Start date
I've got a Utica TS-35 torque driver that I found on eBay awhile back. First class tool, 0-36 in./lb., easy o use. For the (very) rare occasion that I need to go higher I also have a beam-type torque wrench. I really like these--they are the essence of simplicity, and you can calibrate them yourself, without special calibration tools. If the thing should get out of calibration, it's easy to spot--the pointer will not point to zero when the tool isn't under stress. To calibrate it, you just bend it back to zero. Here's mine:
http://www.amazon.com/2955-Torque-Wrench-0-60-Inch-Pounds/dp/B00004SQ3B/ref=sr_1_1?s=hi&ie=UTF8&qid=1344188608&sr=1-1&keywords=torque+wrench+inch+pounds
http://www.amazon.com/2955-Torque-Wrench-0-60-Inch-Pounds/dp/B00004SQ3B/ref=sr_1_1?s=hi&ie=UTF8&qid=1344188608&sr=1-1&keywords=torque+wrench+inch+pounds
Jay Christopherson
Not An Admin
I use the Borka. Worth every penny.
ddkearney said:
Not to rain on anybody's picnic, but remember that the accuracy of the all the torque wrenches in question really isn't the issue here, it's the (highly variable) friction coefficient variation among the individual fasteners, unfortunately. Most torque wrenches are quite accurate and repeatable, but on the best day of your life, tightening, say 8 fasteners on two scope rings, the actual preload variation among each of the fasteners will be 30%, and that is pure dumb luck, not anything the tech installing the fasteners did. A more reasonable/normal level is 35% or more variation, with 100% variation (the highest preload is twice the lowest preload) not that uncommon where a careful multi-step tightening procedure, along with one or more check passes, as necessary, is not used. A torque wrench does two things: it gives a crude, but good enough with most joint designs, idea of where you're at stress wise, keeping the installer from accidently overstressing anything, and it leaves an auditable trail if one keeps a record of the torque applied.
So the bottom line is, buy whatever torque wrench you like and can afford, take good care of it, and enjoy assembling things in a manner that will give a slightly improved fastener to fastener preload variation situation compared to using the appropriate driver and mechanic's feel. But don't believe that the actual preload variation among the fasteners in the joint is particularly small, because it's not. But that's OK, too, beause if the joint required a higher level of precision, you would have been told what kind of thread lube to use, rather than assembling the fasteners dry, and you would have been given an assembly procedure to follow (probably using angular turn; it's cheap, and, because it eliminates friction and the variables it causes while getting fastener to fastener preload variation down around 15%, much more reliable than a torque wrench from a variation standpoint) that didn't use a torque wrench. And if it's really critical, you're into stretch measurement, where accessibility permits, or ultrasonic direct stress measurement (the equipment for that costs as much as a good custom rifle). Bolted joints in most services are very tolerant of preload variation, so don't get too tied up in worries about a torque wrench - be more conerned about using quality fasteners with a good finish, like the ones commonly supplied by scope ring manufacturers and supplied as action screws. The use of a torque wrench is simply a probable bonus, joint quality wise.
So the bottom line is, buy whatever torque wrench you like and can afford, take good care of it, and enjoy assembling things in a manner that will give a slightly improved fastener to fastener preload variation situation compared to using the appropriate driver and mechanic's feel. But don't believe that the actual preload variation among the fasteners in the joint is particularly small, because it's not. But that's OK, too, beause if the joint required a higher level of precision, you would have been told what kind of thread lube to use, rather than assembling the fasteners dry, and you would have been given an assembly procedure to follow (probably using angular turn; it's cheap, and, because it eliminates friction and the variables it causes while getting fastener to fastener preload variation down around 15%, much more reliable than a torque wrench from a variation standpoint) that didn't use a torque wrench. And if it's really critical, you're into stretch measurement, where accessibility permits, or ultrasonic direct stress measurement (the equipment for that costs as much as a good custom rifle). Bolted joints in most services are very tolerant of preload variation, so don't get too tied up in worries about a torque wrench - be more conerned about using quality fasteners with a good finish, like the ones commonly supplied by scope ring manufacturers and supplied as action screws. The use of a torque wrench is simply a probable bonus, joint quality wise.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.