There are a few ways that you can tell what hex key you may need to finish a project tighten a set of screws or loosen an old screw.
Allen key sizes.
Their purpose is largely to serve specialized applications where size constraints and strength requirements need to be met.
These sizes are 1 mm 1 25 mm 3 5 mm 4 5 mm 5 5 mm 7 mm.
Allen wrenches are convenient and helpful.
The m3 and m4 nominal screw sizes have two drilled holes spaced 180 degrees apart.
However the 1 4 sae hex wrench will likely work in place of a 6 5 mm wrench.
Lastly there s one other added benefit to having both sae metric hex keys.
You can find a chart of the allen wrench sizes from any manufacturer.
Drilled head metric hexagon socket head cap screws normally are not available in screw sizes smaller than m3 nor larger than m36.
If you aren t sure what size you need an allen wrench size chart can be a handy tool to get you on your way.
In that case you ll want a range of allen wrenches to make sure you have the right size for every particular need.
Interchangable 0 028 and 0 7mm.
These standard allen keys offer a larger range of sizes than the stainless types.
Less common metric sizes.
Substituting uncommon hex sizes.
The good news is that just about every tool manufacturer has a range of allen wrench sets you can buy.
These allen keys or wrenches from wera feature a hex plus head on the short arm and a six sided ball head on the long arm.
In the united states larger metric half sizes like 6 5 mm aren t standard in most hex key sets.
Stan dard sae hex key sizes inches metric hex key sizes mm notes compares standard and metric allen wrench sizes where they closely match and where they don t wrench equivalence 15 key set.
Hex key size 3 16 1 4 5 16 3 8 3 8 7 16 diameter m16 mio m12 m14 m16 m18 m20 m22 m24 m30 wrench size 7 mm 8mm 10mm 13mm 17mm 19mm 22mm 24mm 27mm 30mm 32mm 36mm 46mm hex key size 3 mm 4mm 5mm 6mm 8mm 10mm 12mm 14mm 14mm 17mm 17mm 19mm 22mm 1 1 1 2 5 8 3 4 3 4 7 8 7 8 1 4 1 2 1 2 2 2 7 8 16 1 4 5 8.
A hex key or allen key is a simple tool used to drive bolts and screws with hexagonal sockets in their heads.
While these metric allen key sizes do exist they rarely appear in your basic allen wrench sets.
Nominal screw sizes m5 and larger have six drilled holes spaced 60 degrees apart unless the purchaser specifies two drilled holes.
Differ ence in 1 1000s of an inch.
Hex plus offers a bigger contact surface in the screw head and so reduces the chance of wear and rounding off the corners in allen head screws.
Allen key also known as hex key hexagon key socket key ln key sizes and its dimensions can be very handy while designing and selecting fasteners for your application.
