Crimping Large Terminals (Open Barrel F-Type M8 Rings)

[revilla]

I need to crimp some M8 ring terminals onto some 4mm² (standard thinwall PVC) cable.

The only M8 ring terminals I can find to buy are as shown in the picture below. Next to them is a female spade terminal designed for 4-6mm². As you can see, the ring terminals are made of substantial brass and the crimp is generally larger and more robust than the spade terminal.

I have a couple of standard crimp tools which cover terminals of various sizes, such as the Durite one below. The largest set of jaws on each is labelled 4-6mm². They will crimp the spade terminals shown above all day long, perfect results every time, but try the ring terminals and i) they nearly break your wrist, ii) they crush the terminals into fragments every time.

My problem is that I cannot for the life of me find either:

• A crimping tool designed for F-type (small bit crimps the conductor, large bit supports the insulation) that will handle bigger sizes than 4-6mm², or
• M8 ring terminals suitable for 4mm² cable that fit a standard crimp tool.

Either of the above would solve my problems! 

Anyone point me in the direction of a solution please?

Thanks,

Andrew

[bosshogg]

Andrew, can you not crimp the small one on, cut the spade off and then crimp the larger one on the top. I appreciate this is a bit of a bodge, but may work.

Alastair

[Wrightpayne]

Andrew,

found these brass ones which seem to take small cables.

http://www.autoelectricalspares.co.uk/ring-terminal-large-m8-non-insulated-84mm-brass-x-10-1544-p.asp

Also, have you tried lubrication on the crimp tool - perhaps a spray with GT85 / WD40 may work??

Ian

[revilla]

@bosshog - The problem is not that the crimp is a bit too big for the wire, it's too big for my crimp tool so I can't manage to crimp it at all.

@Wrightpayne - Yes I thought they might do, until I bought them! They're the exact same ones I've got. Actually ordered a couple of others too from different places which looked right, but they're all the same.

[revilla]

Looks like you can get 8-10mm2 jaws for some of the interchangeable tools such as Sealey which would probably be OK but at £41 for the handle and £21 per set of jaws it's potentially an expensive way to find that they're not right! Actually at those prices would make more sense to buy a complete set but they're a lot of money. http://www.toolandfix.com/sealey-ak3858-h-open-barrel-d-sub-crimping-jaws.html?utm_source=google_shopping&gclid=Cj0KCQjwyYHaBRDvARIsAHkAXcviNYNInKngFcxyA3p0iw0tkndtppI0CW4eKhFSmifrfwnqVFhK7mwaAge-EALw_wcB

[Wrightpayne]

What about modifying the tabs of the crimp with a dremmel cutting disc to the same dimensions as the other one? Ok if you only have a few to do.

Looking at the pictures I think there is too much length of metal being forced into the former of the crimp tool, bottoming out before the tool has crimped fully.

Another approach would be to stop crimping when it gets really hard and release the ratchet mechanism rather than forcing it fully home - this may or may not crimp the wire correctly and could need finishing with pliers or an insulated crimp tool.

Ian

[Drumster]

Not my favourite type of terminal to use but would something like these solve your problem?

[rj]

https://www.ebay.com/itm/BGS-Tools-H-Connector-Crimping-Jaws-For-Japanese-Motorcycles-1413/292613729902?hash=item4421232e6e:g:ujoAAOSwE9RbLD5j

Would probably do with the Sealy crimp tool. You'd still need quite an effort to crimp though

[revilla]

Looks like Jonathan Kay my have come up trumps with these that look right. M8 rings but with more normal crimp dimensions specified for 3-6mm2 wire.

Ordered some, will give them a try.

Thanks for all the suggestions.

https://uk.rs-online.com/web/p/crimp-ring-terminals/7187621/