316 SS and bolt cutters

I am not going to trade qualifications or pedantic detail with anyone but I can tell you as a Chartered Mechanical Engineer who has spent a lot of his life designing and building boats that the following is true.

1. Stainless steel is always subject to work hardening which confuses statistics regarding it's apparent properties on cold working. Anyone who has tried drilling a hole in a piece of stainless steel plate knows that there is a vast difference between this and mild steel regardless of the quoted properties of the material in an annealed state.
2. The shear strength of stainless steel is a moot point. Depending on which ASTM test you do (most being based on the force applied to a tool "punching" a round hole) you can get anything from about .5T (T representing the UTS) to about .8T the latter being mainly on steels that are irrelevant to this subject. I know of no test saying that it is any less than that.
When designing plate couplings a figure of .6T is usually judged to be safe for a bolt or rivet in shear. Your original figures were therefore not unreasonable as you obviously want to look at worst case scenarios.

What does this mean in practice?

As I said before, the most important thing is that the tool is harder than the material being cut. 35 Rockwell C is not excessively hard as cutting tools go but sufficiently hard that it will cut SS rigging wire without a problem.
No one can tell you if you will be able to do it though with a specific 30" bolt cutter because the mechanical advantage of bolt cutters and nut splitters varies considerably. It also depends upon who is doing the cutting. Arnold Swartzeneger would have no trouble, Kylie Minogue might struggle.
My guess is that they are probably OK but I carry 36 inch ones on my boat. Size matters! They are heavy though and needing two hands to wield them is an issue.
Why not just get some spare bits of wire from your local rigger and try them?
Regardless of the science, the proof of the pudding is in the eating. Confidence comes only from knowledge, knowledge comes from experience. Do it! I believe you will find they are perfectly OK.
Edit: I have just looked at hardness values again and tend to think that 35Rc is indeed the material that the cutters will cut rather than the hardness of the blades ( I am used to Vickers too) so I agree they are marginal which makes it even more important that you try them.
 
I used to work opposite a well-known rigging outfit. Watching them cut up old standing rigging from large cruisers was a lesson in how tough it is. Definitely go for the longest-handled cutters that you can find. The trick then is to lay one handle flat on the ground / deck holding it in place with your feet, feed the wire into the jaws, and then lean with all your weight on the upper handle. It was not easy ashore and I dread to think how difficult it would be afloat in a crisis.
 
That's exactly what I do. My Ryobi 18v grinder takes the same battery as my cordless drill. When the drill battery needs recharging, I put on a spare and transfer the newly charged one to the grinder so that it's always ready to go with, as you suggest, a 1mm cutting disc fitted. Both tools and charger are aboard permanently.
 
The technique with the grinder is quite similar to using a chainsaw. Manoevre the grinder so that the rigging wire is in the corner formed by the grinding disc & the guard then you have complete control just one handed. Anyone who has not tried a 1mm disc for metal work should do so. Its like going thro' butter ! When your average Tea Leaf discovers this tool the conventional padlock will go right out of fashion.
 
You all missed the obviouse point - they are BOLT cutters, you need WIRE cutters which have curved blades which grab the wire rather than try and spit it out and are designed to shear rather than nip. The diff in design means you need half the power to cut wire with wire cutters then you need with bolt cutters. Unfortunatly wire cutters are more expensive but if you ever do need them you will be glad of the difference.
 
I seem to be a veteran of some 5 different occasions of mast down around the ears. Early on it was with a cat with 30ft mast and later with trailer sailer with 26ft mast. Now in each case it was in flat water but in each case the rigging was disconnected at the clevis pins.
I was mindfull of rebuilding the rig from the beginning.
Now I realise that with a bigger rig and in rough water I wouldn't want to waste time disconnecting and I do support the requirement to carry bolt cutters.

The mast in each case was a deck stepped mast and the break was near the middle of the mast.
You will need a hacksaw to cut through the mast at the break. It never completely parts.

The other thing that causes real trouble is the mainsail in the track. If you have sliders these will need to be cut off. If as I do you have a bolt rope in the track then you will need to be able to cut the sail, let it all go or as I did tie the whole mess onto the deck and sort it out at home.

The good news is that masts always lay themselves to lee ward so no real danger in the falling.
Cutting SS wire.
In the shed I use scissors or bypass type cutters for 1/8 inch 1x19 wire and 7x19 wire and hacksaw for anything heavier. The bolt cutters tend to just flatten the wire and work much better on solid metal.
So the answer to the big question is to get some scrap wire and test your bolt cutters. olewill
 
I think you'll find that I didn't miss the point at all.

<<< One problem that has been highlighted in several reports is that normal bolt croppers have difficulty with wire as it slips out of the jaws. I was careful to buy a pair that had a notch in one jaw that prevents this from happening. >>>
 
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