CDI vs PI 3/8" Split Beam Decision

S

skeptastic

Joined
Jan 27, 2024
Messages
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Hey everyone! I've been reading thread after thread for the past few weeks, and finally decided to create a thread to see if I can get help with a tool decision. I actually read so many posts by member @Trav that I initially attempted to send this directly to him in a private discussion post, but it appears Trav doesn't do private convos, which I definitely respect. I'll go ahead and paste what I'd just written to Trav below, and hope that folks with the appropriate knowledge can help me out. I'll leave out my intro to Travel, so it'll get straight to the point haha.

I am super intrigued by the Precision Instruments 10-50 ft-lb split beam torque wrench, but it seems like they are one of the few well-regarded brands that don't include a detailed calibration certificate. I found one for about $145, which is outstanding given the 10-50 lb range is exactly what I need. But, I figure I should probably send the unit out to be calibrated if I purchase it, which adds to the cost and time to have it ready for use.

On the other hand, I discovered that CDI sells a 120-600 in-lb split beam, so same range, but I believe they include a detailed calibration certificate, which saves me the trouble of having to send the tool off for calibration. In addition, it appears that CDI still makes Snap-On products, while PI no longer is in that employ, which sort of adds to the confidence in their product. I've found the CDI unit for $235.

It feels like the two units will come out to nearly the same cost, but the CDI will be ready to go and $235 sounds like a hell of a bargain for such a highly touted product made by a premier company. Let me know what you all think, when you have time, and thanks for your time and insight!
 
MY PI came with a calibration sheet.
I have the

Precision Instruments PREC3FR250F 40-250(?)​

 
Rand said:
MY PI came with a calibration sheet.
I have the

Precision Instruments PREC3FR250F 40-250(?)​

Click to expand...
Did it simply state that it was calibrated to be within +/- 4%, or did it have details of the three different torque levels that most companies include which show that the calibration was done? Everything I am seeing in recent PI torque wrench posts on various sites shows certificates lacking the detailed info, and just a. generic statement of calibration.
 
I'll go check it. brb with an edit
I must have been thinking of my other torque wrench this one just says within 4%
 
I have no info on this model torque wrench you're asking. But I can speak to torque wrench calibration services. Sent my 3/8" and 1/2" Quinn Digital Torque Angle wrenches to Angle Repair & Calibration in West Virgina. Within a week had both wrenches back calibrated. Cost $35 per wrench plus return shipping.

You can pay more to get a certification for them. But for my use I just wanted to make sure they were calibrated (building an engine).

anglerepair.com

Angle Repair & Calibration Service | Calibrate and Repair Your Torque Wrench | Beckley, WV

Located in Beckley, WV, Angle Repair provides nationwide torque wrench repair. Our trained technicians will calibrate or repair heavy duty torque wrenches.
anglerepair.com anglerepair.com

How this is related is that I was going to buy new CDI wrenches to replace my 1-2 year old Quinn because I had no clue if mine were accurate or way off... or what their "deal" was. But I could never find accurate or detailed info that'd tell me "yes if you buy this wrench it'll be XXX calibrated and here's the certification". Beyond of course a SnapOn wrench or something from a definite dealer. So I decided to just get mine calibrated.

Perhaps this could help you in buying a cheaper cost wrench (not necessarily a junk wrench) via a cheaper retailer?
 
redhat said:
I have no info on this model torque wrench you're asking. But I can speak to torque wrench calibration services. Sent my 3/8" and 1/2" Quinn Digital Torque Angle wrenches to Angle Repair & Calibration in West Virgina. Within a week had both wrenches back calibrated. Cost $35 per wrench plus return shipping.

You can pay more to get a certification for them. But for my use I just wanted to make sure they were calibrated (building an engine).

anglerepair.com

Angle Repair & Calibration Service | Calibrate and Repair Your Torque Wrench | Beckley, WV

Located in Beckley, WV, Angle Repair provides nationwide torque wrench repair. Our trained technicians will calibrate or repair heavy duty torque wrenches.
anglerepair.com anglerepair.com

How this is related is that I was going to buy new CDI wrenches to replace my 1-2 year old Quinn because I had no clue if mine were accurate or way off... or what their "deal" was. But I could never find accurate or detailed info that'd tell me "yes if you buy this wrench it'll be XXX calibrated and here's the certification". Beyond of course a SnapOn wrench or something from a definite dealer. So I decided to just get mine calibrated.

Perhaps this could help you in buying a cheaper cost wrench (not necessarily a junk wrench) via a cheaper retailer?
Click to expand...
Great input and suggestion. I'd already have gone with a cheaper one from Tekton or Icon if they had one in the 10-50 ft-lb range. Most cheaper companies have the 20-100 ft-lb as their lowest ranged, and I specifically need that low range. If I wasn't locked in on a split beam I could always get a 10-80 and a second in-lb wrench, but for my simple purposes, the 10-50 checks all of the boxed and simplifies things in terms of not needing a 1/4 to 3/8 adapter and such. But it seems like it's only when you get to the level of PI, CDI, Norbar and such that you start seeing those 10-50ft- lb or 120-600 in-lb split beams.

Honestly, for $35 + shipping, that would make the PI unit a solid deal. I just figured someone might be able to say that CDI definitely includes the calibration certificate, and kind of steer me in one direction or the other. All the tests I've seen about the PI's out-of-the-box show they are often far outside of the +/- 4% spec, which is concerning. People do report sending them off to be calibrated and then having a perfect unit due to how precise they are. They just don't seem to come with high accuracy in stock form. I'd kind of rather just have it ready to go out the gate, but CDI listings also don't mention a certificate, though I've seen plenty of posts on various forums showing images of the certificates with detailed accuracy range at multiple levels of torque.
 
Last edited:
Trav said:
I will look tomorrow AM and post a picture if it has one. I have had it for a long time and it is still accurate.
Click to expand...
You referring to the PI or CDI?

I just watched a video that showed the PI's accuracy being off by 5%, but the guy's calibration tool was unstable (moved in the vise when he initiated his first torque and he never fixed the issue as he continued testing). In addition, he was quick-torquing and using a ton of force instead of slowly pressing to arrive at the click point. I wonder how many reviews saying the PI accuracy is off are based on this video (hour-long video done by an outfit called Grass Roots Sports).
 
So I finally found some old footage of a Snap-On 3/8 unit that looks exactly like the PI unit, which of course points to the fact that PI at one time made the wrench for Snap-On. This isn't anything you all don't know, but since CDI now makes the Snap-On unit and it has a more modern design (which Tekton and Icon have mimicked of course), do you think that there is something in the newer design that might make it a better unit than the older design of the PI torque wrench? If you could get the PI or CDI for the same price, would there be any reason you'd choose one over the other, or would it no really matter either way?
 
After watching a few more videos and reading up, it seems like a lot of tests are questionable, and way more folks report PI as being extremely accurate out of the box and holding that accuracy for some time. I also have no way of knowing if testers are using old PI units that have been in use for some time, or new ones. When testing against Tekton, Icon and such, it's clear those items are new, but not with the PI. I also like the idea of the non-rubber handle of the PI, the cost, and the fact that they've been around since 1938. I'm gonna go with the PI unit, pending any additional insight any of you might need up sharing that could steer me away.
 
skeptastic said:
You referring to the PI or CDI?

I just watched a video that showed the PI's accuracy being off by 5%, but the guy's calibration tool was unstable (moved in the vise when he initiated his first torque and he never fixed the issue as he continued testing). In addition, he was quick-torquing and using a ton of force instead of slowly pressing to arrive at the click point. I wonder how many reviews saying the PI accuracy is off are based on this video (hour-long video done by an outfit called Grass Roots Sports).
Click to expand...
PI. These split beam TW use simple internals which helps them maintain their accuracy over long time usage, there are no springs so there is no need set to zero after use, the setting can be left at any number. The quality of the steel is important for the longest life and CDI and PI are both high quality, I would not pay extra for a certificate unless you are required to have a NIST or other standard as required for some jobs. You can get a pretty good idea by checking it will a digital torque adapter, if it is questionable sent it out for calibration.
Norbar issues a UKAS certificate on their pro tools which is similar to NIST and also accepted. Stahlwille which is Germany's best has implemented DIN ISO17025:2018 at the production level for every TW and is accredited by DAkkS.

Any video of some guy pulling on the tool is almost worthless and should be taken as entertainment only, you can make any tool inaccurate just by how it is used.
The PI just has a simple certificate but it is traceable with the tools serial number and tested on NIST certified equipment. I have had it calibrated a few times and it was still well within specs. When I bought my CDI tools I didn't buy the certificate, I checked it with a digital torque adapter then after 6 mo I had it calibrated anyway. Do not get hung up on that.
IMG_0166.JPG


This is Norbars UKAS certificate. 0.47% accuracy. I send this one back to Norbar occasionally, it is always less than 0.5%.

IMG_0168.JPG
 
I don't believe PI does a full calibration check on each torque wrench they manufacture. If they do, why not include a real calibration certificate, including test data, with each wrench? It would cost next to nothing to print it out.
They are probably taking a statistical approach, and checking every 10th or 20th or 50th sample.
 
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