bosch shears weirdness

[chunkolini]

I was using my Bosch gsc16 shears the other day. Ive had them for years and used them loads, last replaced the blades a few years ago.
I was cutting out oval of 1.2mm mild steel.
I put the shears down and heard a 'CLICK' and was pinged just above the eye by a tiny splinter off the jaws. It drew blood.
Weird.
And how odd that tiny projectiles always go for the soft sensitive bits of the body.
There's a corner off one of the blades and the rest of the surfaces are worn.
Fifty Quid for two new blades, each the size of a little finger nail

 

[mike 109444]

When I have seen those sheers in the past (mainly on this site) I thought that the cutters did look a lot like the tips used on lathe and milling cutters so just a thought with so many on here using the indexable tooling, if you post up some measurements it could be that there are some cheaper alternatives that might fit.
And you eyes have a magnet attraction to steel that guarantees any flying particles of metal will find them

 

[chunkolini]

Thats an interesting idea.
I'll try to remember that for next time.
It's amazing how long they last really.
Out of curiosity I'd love to hear any theories regards why the blade suddenly shot at my eye. the splinter was super tiny, just the corner of the blade.
I'm always careful using them, never twist the blades or force them, and the shears were turned off and sat on the bench when it happened.

 

[pedrobedro]

Out of curiosity I'd love to hear any theories regards why the blade suddenly shot at my eye.

Just a thought, is your head magnetic ?

 

[mike 109444]

Think you will find that the tips for lathe and milling tools (which may be made same as your shears) are referred to as "sintered" material. This if I recall is a process where powered/particles of metal are put into a mould and under heat and pressure are formed into the required shape including the cutting edges so next to no grinding required ! This does make for a brittle cutter though, hence why it is so easy to chip them.
All the above may be wrong though as it's been nearly 25 years since I was in a machine shop environment!

 

[mike 109444]

Think you will find that the tips for lathe and milling tools (which may be made same as your shears) are referred to as "sintered" material. This if I recall is a process where powered/particles of metal are put into a mould and under heat and pressure are formed into the required shape including the cutting edges so next to no grinding required ! This does make for a brittle cutter though, hence why it is so easy to chip them.
All the above may be wrong though as it's been nearly 25 years since I was in a machine shop environment!

Does he point North when say floating on a lilow OR even hand gliding ?

 

[Morrisman]

Sort of similar, a month ago I carefully poured a bunch of fancy glass marbles and stuff into a large glass spherical vase thing I've had for years, about 14" diameter. It looked nice and pretty, but about six hours later there was a very loud 'crack', and several big fractures appeared all round the vase. It didn't fall apart, but was too dangerous to leave on display. I very vaguely recall hearing something about glass reaction like this. Any ideas what could have caused this? The marbles were loose, not wedged oil, and only filled 1/3 of the vase.

 

[mike 109444]

I would imagine that one of the marbles was pressing hard against the glass bowl causing a pressure point.
Glass is a weird stuff, see if you can find maybe on youtube the episode of QI where Stephen Fry crushes a glass blob (think glass tadpole!) and it explodes due to the tension stored in the glass blob being released

 

[Screwdriver]

Sort of similar, a month ago I carefully poured a bunch of fancy glass marbles and stuff into a large glass spherical vase thing I've had for years, about 14" diameter. It looked nice and pretty, but about six hours later there was a very loud 'crack', and several big fractures appeared all round the vase. It didn't fall apart, but was too dangerous to leave on display. I very vaguely recall hearing something about glass reaction like this. Any ideas what could have caused this? The marbles were loose, not wedged oil, and only filled 1/3 of the vase.

Prince Rupert’s drops. Drip molten glass into water to quench it into a highly stressed state. It is related to toughened glass but the tadpole shape means one end is weak and the other unusually strong. Clip the weak end of the tail and it explodes into dust. I keep meaning to make some...

As for the marbles in a bowl, I am wondering if they didn’t get jammed together and thermal expansion caused extreme pressure at a single point. Glass is indeed weird stuff.

 

[Morrisman]

I saw a demonstration in London’s science museum decades ago where the broke the tail off one of the blobs, pretty impressive.

Not sure how the marbles could have jammed at all, there was so many all loose in there, but you never know.