Metric or Imperial

brouwpa

brouwpa

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I have just bought a set of Wega Hex keys in Imperial as they were local to me! Which manufacturers would these apply to? Or have I cocked up and should have bought metric?
Cheers
 
Both. Always both.

I recommend the Wera "Hex Plus" sets, I am yet to strip anything with mine, good quality tool that is useful for most applications.
Only time I've switched away from them is for counterbored fasteners, as the colourful sleeves can't clear the bore of the same sized head.

If you use a key that's a hair undersized you'll be testing the metallurgy of the tools and fittings rather than taking advantage of the geometry of the tools. The best was I can think to illustrate this is by looking at the difference between a phillips (PH) and a pozidriv (PZ) screw. Using the wrong driver will knacker the fastener right quick because they just don't engage properly:
1771239031961.webp

Even if from the top of the fastener, it looks like you have inserted the bit well.

(my condolences out to all your JDM car enthusiasts that had to also get a set of JIS drivers, and have found our that not all JIS fasteners use the little dot to indicate that they are JIS and not PH)

Conversion charts between Standard/Imperial and Metric are heretical texts, and should be burned.
Star drive superiority. ⭐
 
I know doesn't answer the OPs original question, but anybody in the market for a set of hex keys, I can recommend this set from Magnusson. One side is metric, the other imperial in pretty much every size you will ever need. Bought it primarily for the 0.05 inch imperial for a Crosman 2250 Ratcatcher. This set was < £15 from Screwfix.

IMG_0648.webp
 
Think my old Daystate had a mix of imperial and metric screw heads and threads…

Seem to recall older Theobens possibly have a mix of imperial and metric????

American guns are likely to have imperial size threads and cap heads (where used)
 
Bazzatron said:
Both. Always both.

I recommend the Wera "Hex Plus" sets, I am yet to strip anything with mine, good quality tool that is useful for most applications.
Only time I've switched away from them is for counterbored fasteners, as the colourful sleeves can't clear the bore of the same sized head.

If you use a key that's a hair undersized you'll be testing the metallurgy of the tools and fittings rather than taking advantage of the geometry of the tools. The best was I can think to illustrate this is by looking at the difference between a phillips (PH) and a pozidriv (PZ) screw. Using the wrong driver will knacker the fastener right quick because they just don't engage properly:
View attachment 904187
Even if from the top of the fastener, it looks like you have inserted the bit well.

(my condolences out to all your JDM car enthusiasts that had to also get a set of JIS drivers, and have found our that not all JIS fasteners use the little dot to indicate that they are JIS and not PH)

Conversion charts between Standard/Imperial and Metric are heretical texts, and should be burned.
Star drive superiority. ⭐
Click to expand...
A very sensible reply. Not many people know that the JIS system exists. How many of you stripped down your 1970s Honda, Suzuki or Yamaha in that era and knew that JIS existed. I wonder if you used Philips screwdrivers and mullered the ends
 
Steve217 said:
I know doesn't answer the OPs original question, but anybody in the market for a set of hex keys, I can recommend this set from Magnusson. One side is metric, the other imperial in pretty much every size you will ever need. Bought it primarily for the 0.05 inch imperial for a Crosman 2250 Ratcatcher. This set was < £15 from Screwfix.

View attachment 904242
Click to expand...
I ve got the same set in a grey colour Badged as Fineline so guess they are all rebranded, seem ok, until you lose one!
 
norfolkngood said:
A very sensible reply. Not many people know that the JIS system exists. How many of you stripped down your 1970s Honda, Suzuki or Yamaha in that era and knew that JIS existed. I wonder if you used Philips screwdrivers and mullered the ends
Click to expand...
Fasteners is a bit of a special interest of mine. There really should be a point in every practical person's life where they strip another head and this "I guess it's about time I learned why I keep ruining these things...!"

Thanks for the vote of confidence! :)

If anyone has 15 minutes over a coffee break and would like to learn more, including the secret canadian screw that we never really got here in the UK for the most boring of reasons, I would highly recommend this short talk by The History Guy.

 
As a rough guide I associate imperial with British manufacture up to around 1950/60, possibly a bit later, when metric seemed to become the norm. But, and a big but, you can never tell. It has been mentioned that Daystate sometimes mix metric and imperial. These days I assume a metric hex head size or thread until I find the metric tool does not fit when I try imperial and even then I may have to delve into the BA sizes. However, as another guide most European makes will be metric but you can still get caught out when it comes to thread sizes as some manufacturers throw a 'metric fine' thread into the mix... as in some open sight parts and other narrow gauge screws. Hey ho ... luckily the 1/2 UNF 20 seems to have been accepted as the standard for moderators/silencers although 10mm does crop up. This all illustrates that a good range of tools is priceless.
Cheers, Phil :)
 
And philips were designed to cam out to stop them being overtightened. Can also bugger them if they are tight when you want them out. Most Japanese electric tools use JIS as well as the motorbikes.
Hex Plus as patented by Wera, are designed to work on the flats not the corners that's why the work so well.
 
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Old is good. Let's return to the days of all slotted screw heads & proper turnscrews to nip them up. If buggered up, they can be tapped over with a light hammer & slots filed, re blued with heat & oil...
Effective & less clutter on a bench.
 
Philthunder said:
And philips were designed to cam out to stop them being overtightened. Can also bugger them if they are tight when you want them out. Most Japanese electric tools use JIS as well as the motorbikes.
Hex Plus as patented by Wera, are designed to work on the flats not the corners that's why the work so well.
Click to expand...
And Japanese cameras use JIS drivers as well, unsurprisingly. I'm just glad I stumbled across that fact before trying to detach the redundant "rabbit ears" from a vintage Nikon lens
 
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