I ran into a predicament this weekend, and a more minor one the week before. Not all hex keys fit fasteners the same.
I think this could partially be due to the fasteners themselves, but hex key coatings and tolerances might have also come into play.
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It was the strangest thing. I was assembling an 80/20 cabinet frame, with dozens of button head cap screws. 80/20 is a system of t-slotted aluminum extrusions, used for building almost anything you could imagine. I’ve done this kind of work many times before.
So I whipped out a newish set of Bondhus hex keys, started with the 3/16″ key, and it wasn’t a smooth fit. The Bondhus keys are coated with a GoldGuard finish, similar to the ones shown here, which I like because it makes them easy to clean.
The darned thing didn’t slip in easily.
So I went and grabbed my PB Swiss hex keys, and they slipped in easily and effortlessly.
Umm…
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I like Bondhus hex products since they’re inexpensive, well-built, and they worked quite well for me in the past. I’ve been buying their products for maybe 10 years, with my first experience being a blind ball driver purchase from McMaster Carr.
But this time I was boggled. Maybe the tolerance of the fasteners are a little tighter than usual. They weren’t standard button head cap screws, they were 80/20’s special flange head ones.
Maybe the PB Swiss are engineered to a closer tolerance, with their machined tips.
I’d like to think that maybe the Bondhus’s failings were due to a fastener tolerance issue, rather than the coating being too thick, or that the sizing was off for a different reason.
But at the end of the day, I was just extremely happy that I had my PB Swiss hex keys within reach. It would have been a nightmare to use the Bondhus drivers on several dozen ill-fitting fasteners.
I noticed differences with both ball and straight ends, which makes me think that maybe the PB Swiss fasteners simply fit better with these particular cap screws. I’ll dig out a box or two of different brands’ 5/16″ cap screws to check for it. But regardless of the outcome, this was an eye opener that sometimes different hex keys – even good ones – can make the difference between an application being easy breeze and frustratingly finicky.
Have you found the same?
Buy Now(PB Swiss Hex Keys via Amazon)
Buy Now(Bondus Hex Key Set via Amazon)
Conor
We have a few of those exact Bondhus hex key sets at work, and they don’t fit in most fasteners. Not sure why, but nice to see a corroborating experience.
Tim
Same here with Bondhus ones that are color coded.
This happens as well when you jump from some of the cheaper sets to my wiha’s and other more expensive sets.
mike aka Fazzman
Stu,
Your experience sounds about right. been using Bondhus stuff formany many years and certain fastener types they just dont work very well. On standard cap screw heads never have much issue,althou they dont they dont always fit as tight as one would like that could be any number of issues.
john
Surely you own some good quality calipers right? Measure the screws and measure the Bondhus. Case closed.
Stuart
Hmm… sounds like an application for my micrometer and some small ball gages, if I can find them!
Jerry
While you are at it, measure your PB Swiss wrench, as well. I’d be curious how they compare to the Bohndus. Im guessing that the PB Swiss, being ng machined, should be more true to size. Im guessing Bohndus takes hex shaft of a certain size and just forms it to shape, which puts them at the mercy of the shaft maker. If drawn through a die nearing the end of its life, the wrench will likely be a tiny bit oversized.
Hang Fire
Also look under magnification for burrs.
Jason
john is right in that you need to measure the screws and or tools with a caliper or micrometer.
We ran into this issue with a product we make at work. When you’re buying thousands of machine screws from McMaster Carr and never had issues and then you suddenly have issues you know something is up. One of the guys measured out a whole bunch, pulled up the ANSI standards and sure enough McMasters supplier had a bad batch of screws that were out of tolerance. For most it wouldn’t be an issue but the bits didn’t fit into the head of the screw and our designed used recessed screws and the oversized heads were binding before being fully seated.
Bondhus and PB might both be within acceptable standards since you have an allowable tolerance and it’s the fasteners that aren’t up to standard. Or vice versa. It’ll be interesting to see what you find out!
Hang Fire
I would put my money on the fasteners being out of spec, but the micrometer will tell the true story.
Hang Fire
and, er, inside calipers.
Rod
This has become a pet peeve of mine over the years: hex keys that don’t fit! Almost more aggravating are the ones that are too small. They will invariably strip the head of the fasteners. I have gone exclusively to Wera Hex Plus hex key sets now. Their marketing claims have been borne out through extended use in the shop. They are precision fit and they don’t strip out fasteners. I think they do have a better profile than “normal” hex keys from Allen, Elkind, Bondhus or others. The bonus is that they are not more expensive than other sets. McMaster Carr has them in either metric or inch sizes http://www.mcmaster.com/#57185a61/=131ako5. Although they are not listed by brand name, I have discovered that these are the Wera brand because they use the term hex-plus in the description.
Kyle
When it comes to 80/20 I’ve sometimes found the sockets on the proprietary screws (e.g. truss head with special large flange, black oxide) to be poorly sized.
Stuart
The same issue happened last week, with different Bondhus drivers. I was putting together a mobile workbench.
My inch hex keys didn’t work. My metric hex keys didn’t work. I ended up using a loose-fitting hex bit and then the junky freebie Allen key for final tightening.
BonPacific
I’ve used some PB-swiss hex keys at work, but I’ve never invested in a quality set personally. I have a bin of cheap packs and free keys that came with various tools. Many of the cheap keys fit my 14″ taiwanese knockoff bandsaw perfectly, but my $300 Veritas hand-plane only works with some of the keys that are all nominally the same size.
Better tolerances on the keys increases the likelihood they will fit, but never assures it. Especially if you are using cheap hex-screws that could vary wildly. Perhaps bondhus sizes their keys exactly, and PB-swiss undersizes theirs a hair to ensure they will work with any fastener in that size. This is purely speculation. It could also be that the casting on the screws 80/20 uses has been used past it’s lifetime.
My point here is that I wouldn’t trust even the highest-quality hex keys to fit every fastener every time.
Joe
You are correct, based on this article anyways, although it would always be good to verify their findings with a larger sample size. The chart with the measured tip sizes is near then end. http://www.bikeradar.com/us/gear/article/home-wrench-put-a-hex-in-your-hand-42917/
Fazal Majid
Does anyone make hex-ball type power screwdriver bits?
fred
Bondhus and Wiha do – probably others as well
Drew M
Bondhus may be well known but I’ve never liked their tools. The steel they use is too soft and they’re not precisely ground.
IMHO, a good 1.5mm hex driver is my benchmark. They don’t lose their corners and fit tightly. The good ones also won’t twist very much when torque is applied.
Too bad my favorites are no longer made.
Dan
It always amazes me to hear that people rely on hex keys for so much work. Why do hex drivers and t-handle drivers get so little love? You don’t even need to use them once to see how much better they are! To me, hex keys serve a purpose but are certainly not my first choice for hex screws.
Stuz
Agree !!!
Stuart
I’ve got T-handles, P-handles, and a set of Bondhus drivers, plus some ball hex bits. Sometimes traditional Allen wrenches are the best for reaching fasteners in weird angles and corners, or past obstructions.
Rory
A tight fitting hex key can only be of benefit right? Sure they might take a little work but the wont slip and damage fasteners or knuckles… for general work i use a folding set of keys and a set of 1/4″ Drive hex keys.
Stuart
By tight fitting, I mean that the hex fasteners won’t properly engage a fastener. A ball hex has a slightly easier time, the straight hex just wouldn’t get in there. So wth very shallow engagement, and it requiring a lot of work even to get that engagement, there’s more slippage, more time wasted trying to access the fastener, and very little torque transmission.
Bleo
This is a major problem for those of is in the RC world. When dealing with endless small fasteners in the 1-3mm range none of the major tool manufacturers make drivers to the tolerances needed. I’ve tried Wiha, wera, bondhus, and pb swiss. The drivers made by the small company MIP put them all to shame. I just wish they made bits/drivers of all sizes.
Drew M
Have you tried the Scorpion tools?
I love Wiha’s phillips drivers but don’t really care for their hex drivers.
T
I have had some very expensive bits not fit, cheap bits not fit, etc… I dont think price is the only factor. The expensive bits, ultimately, didnt fit due to the coating – traded out for non coated variants, problem solved. Cheap bits were a mix of poor tolerance/manufacturing and coating as well. I stick with non coated/ blkoxi bits these days. See this problem more with torx than hex though.
Toolfreak
I would agree with the general idea that the Bondhus stuff just isn’t made to the tolerances that the PB Swiss stuff is. The cost reflects that. I have considered them in the past, but decided against buying any of their stuff based on the quantity of negative reviews about the sizing and lack of strength.
I keep a like-new set of the old school USA-made Craftsman hex keys around just in case I run into stuff like this and need hex keys that I know are sized right and will get the job done. I have a few cheap hex sets that work fine for most things, but it’s good to have a higher-end option in case you run into more precise fasterners where sloppy cheap tools won’t work.
This is also why I keep a set of both standard and metric sizes in everything from hex keys to sockets and wrenches. Sometimes a standard size will fit where a metric one won’t, even if it’s actually a metric fastener.
voodooaw
The most stupid bit I owned are the Wera ADC Series bits. They are basically normal impact bits with gold and diamond coat. Since the diamond coat is much thicker than the common chrome plate, the bit become too large to fit into some bit holders. I checked the dimension with a micrometer, and they are larger than the ISO or DIN standard.
MazakJak
Recently bought a batch of Bondhus 5/64 socket keys that would not insert into the appropriate SHCS’s . The wrenches measured .0792 across the flats. ASME B18.3-1998 standard states the size should be .0781 max to .0771 min. Oversize wrenches. Bondhus needs to audit their QC department.
Teddy
Never used Bondhus, but have some experience with “precise tools” (PB, Stahlwille, etc.) and bad screws and furniture. Mostly screws are greatly out of specs.
German made inox screws with inner hex are tight, chinese are loose.
Some SPAX screws have really oversized PZ cross.
Some diamond-grip coating bits don’t fit into precise screws.
Once I had to scrub powder coating from nuts because Stahlwille spanners are really tight to specs and thick powder paint didn’t fit inside.
Once I’ve faced really cheap nuts, cut from thick sheet metal somewhere between 10 and 11 mm in size and only adjustable wrench will fit every one of these …
So, only calipers will tell who is in specs, but none will predict what is better in particular case … )))
Alex
Found this while searching Bondhus socket fit… .. yeah, I think they like to make those hex drivers big. Seem Great for Socket head cap screws, but the button head and flat head seem to be right on the “nominal size” The ANSI spec for imperial size allows the socket to be nominal+0. I think the metric insists on the socket being a little +.
I have a hunch that the best hex to start with to make the ball drivers is just a little bigger than the best hex to use plain as hex, and that getting separate sizes drawn would be expensive. Just a hunch. I just micrometered a bunch of T-handles and they all seem a hair over!
SPAX… SPAX is the Devil. A few years ago I got some SPAX screws to put together some shelves, and wow. Perfect Philips #2 heads. These were the best screws I had ever used.. Self drilling, no splitting, fit the driver tight, good holding, wow.
The Best Screws Ever! Fastforward to the middle of the night (all stores closed) on a project a few months ago and I’m stripping bits and heads left and right. SPAX has come up with a Philips+Square that sacrifices torque and fit on the philips. SPAX has come up with a Torx screw that has a little circular thingy in the middle just to make sure no other Torx drivers really fit right in it. I can’t remember all the details, but things were quite unpleasant. Lord help you if you round or lose that Torx before you finish the box.
There’s also a special place in hell for the people that “improved the Torx” with a socket that’s sort of backassed compatible with the old Torx and a Driver that looks very close and is often marked the same as the old driver.