Alf
Established Member
At least you spotted it, Scott. I had a tiny dink in the toe of mine and couldn't work out where that scratch was coming from. :-k Re-honed the iron and everything before I realised. #-o :lol:
Cheers, Alf
Cheers, Alf
Clifton: why the lack of ductile iron?
- Thread starter woden
- Start date
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That's what having a brother who's a ferrous metallurgist does for you! I recall him explaining that SG was introduced sometime during WWII and was initially used as a way to speed-up production of castings used in things like tanks and guns the big advantage being that "green" castings could be machined within days of production rather than having to weather for 3 to 12 months before machining. The improved machining properties were a bonus, it seems.woden":3f1gr2uc said:
It is interesting that he (the bro) has a particular bias against certain types of tool steel, preferring oil-hardening steels over air-hardening ones for the ultimate in sharpness but telling me that this requires somewhat greater skill on the part of the heat treatment plant to achieve a consistent result. Perhaps this is the case with Clico - they may feel they don't need to go to SG on the grounds that their more traditional approach of producing a malleable iron is potentially superior to the SG method, because they possess the requisite traditional metallurgical skills. Whatever else Clico certainly have an excellent reputation for quality specialist tooling in the aerospace industry, surely one of the fields they major in.
Scrit
Scott
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Rob Lee":3u9eu00n said:
Rob, you're a gentleman sir! I have to admit I didn't use the plane for a good while after I got it because it just seemed spoiled somehow. Crazy I know but I had been waiting for it to arrive for months so I was a bit disappointed when it arrived with a bent nose. Not to worry though, it's getting full use now and I'm very impressed with it thankyouverymuch!
Alf":3u9eu00n said:
mmm, couldn't really have missed it. It seemed bigger than it looks on the photos. Maybe that was just cos it looked bigger through the tears!! :wink:
Cheers
bugbear
Established Member
Alf":308jbl4b said:
A chippy doing some work for me had a similar problem.
The fact that he stored his #5 and #4 in his canvas tool roll along with everything else may have been a factor...
BugBear
Alf
Established Member
Ooo, I never dun nuffink, guv. It came that way!* Heck, you know how careful I am with my planes, aside from a small drilling and tapping issue...
Magnified by the tears; ooo, that's good, that is. Subtle. :wink:
Cheers, Alf
* You've got my address I think, Rob...? Kidding, just kidding! :lol:
Magnified by the tears; ooo, that's good, that is. Subtle. :wink:
Cheers, Alf
* You've got my address I think, Rob...? Kidding, just kidding! :lol:
matthewwh
Established Member
I don't know if this will add anything, but I was being shown around the Clifton factory on the day when they did the drop test that woody mentioned and actually got to watch it.
The test was repeated several times and the sole was re-tested for flatness against a granite bed and then against a 'grade A' straight edge in the same way as the plane bodies are checked before they leave the factory. In total the two foot long, 11lb plane was dropped five times from 18 feet and was still within 2 thou of absolutely flat (their normal working standard is 1.5 thou.)
It is for this reason that Clico use fully annealed grey iron - it takes them two days to treat the castings but by the time they have finished with it, the grey has almost as much impact resistance as ductile, but it won't bend or deform on impact. So if the unthinkable does happen, you can pick the plane up and carry on using it, with no loss of flatness or squareness.
In order to preserve the iron in this state, all of the machining operations, including the removal of the extra shaping, are performed at one fifth of the normal speed, thereby minimising the chance of heat building up and altering the microcrystalline structure of the iron. Despite the difference in basic material costs it would actually be cheaper for them to use ductile because it is much more forgiving to machine. To the guys in the factory though, that would have been an easy option rather than a test of their skills as some of Sheffield's most experienced metalworkers to produce something better.
The test was repeated several times and the sole was re-tested for flatness against a granite bed and then against a 'grade A' straight edge in the same way as the plane bodies are checked before they leave the factory. In total the two foot long, 11lb plane was dropped five times from 18 feet and was still within 2 thou of absolutely flat (their normal working standard is 1.5 thou.)
It is for this reason that Clico use fully annealed grey iron - it takes them two days to treat the castings but by the time they have finished with it, the grey has almost as much impact resistance as ductile, but it won't bend or deform on impact. So if the unthinkable does happen, you can pick the plane up and carry on using it, with no loss of flatness or squareness.
In order to preserve the iron in this state, all of the machining operations, including the removal of the extra shaping, are performed at one fifth of the normal speed, thereby minimising the chance of heat building up and altering the microcrystalline structure of the iron. Despite the difference in basic material costs it would actually be cheaper for them to use ductile because it is much more forgiving to machine. To the guys in the factory though, that would have been an easy option rather than a test of their skills as some of Sheffield's most experienced metalworkers to produce something better.
Paul Chapman
Established Member
That's very helpful to know, Matthew. Always knew my Cliftons were good, but having read your post I now know that they are even better than I thought they were 8) 8) :wink:
Cheers :wink:
Paul
Cheers :wink:
Paul
Philly
Established Member
Makes a lot of sense, Matthew!
Thanks
Philly
Thanks
Philly
Paul Kierstead
Established Member
Clifton really needs to bring their marketing up a notch. That is fantastic stuff for a web page, a pictorial, etc. (hell, the drop test would probably make a good YouTube video). Those kind of details are what sell higher prices stuff.
MrJay
Established Member
They also need to practice getting the stamp on their cutting irons a bit nearer the middle.
MrJay
Established Member
Does getting the maker's stamp off centre improve the cutting action or accuracy of the plane?
MooreToolsPlease
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I very rarely plane with the plane directly under my eyes, usually it is to the side, perhaps it being off centre is actually to compensate for this so that when you look at it, it is centred :lol:
Either way, the stamp isn't at the business end so i dont see what difference it could or couldn't make
Either way, the stamp isn't at the business end so i dont see what difference it could or couldn't make
matthewwh
Established Member
A valid point and I understand that they are already working on one, as usual though they don't want to go at it half-heartedly, so it may take some time.Paul Kierstead":2rl7bt57 said:
Also, although the recent flooding didn't affect the machine shop, the foundry did suffer a drenching and many of the employees homes were also hit, so it will be a week or two yet before they are back to full production, let alone marketing.
In the meantime I have added some more information to our Clifton pages for anyone interested in the design and manufacturing processes.
AHoman
Established Member
matthewwh":3jgjp218 said:
Could you please post a link to these pages?
Thanks,
Andy
matthewwh
Established Member
Sure.
There's one for the
Clifton Planes
and another one for the
Blades & Chipbreakers.
Clearly there is a limit to how much info I can squeeze into the space available, but if you have a question you can always drop me a PM and 'll be happy to help.
There's one for the
Clifton Planes
and another one for the
Blades & Chipbreakers.
Clearly there is a limit to how much info I can squeeze into the space available, but if you have a question you can always drop me a PM and 'll be happy to help.
AHoman
Established Member
Thanks for the links Matthew.
MrJay
Established Member
matthewwh":2el88bxl said:
How the hell did you find irons with the stamp neatly positioned near the middle? Or did you resort to photoshop?
matthewwh
Established Member
Hi MrJay
In the interests of accuracy and originality all of our photos are taken specifically for the site, we don't use stock images. For the vast majority of them, the only editing we do is to add the black backgrounds and occasionally tweak the exposure slightly to give a true representation of colours.
I believe the stamps are applied with a spring hammer to the forged blank. Picture an anvil suspended between two car suspension springs, and a bloke with a big pair of tongs trying to get a 50p sized stamp in exactly the right spot on a slightly less than A4 sized sheet of metal, with uneven edges, at 1000 degrees.
The blades are cut out afterwards with a laser, which is a much more precise operation. However, the blade is lined up with reference to the grain of the steel, not the position of the stamp.
If you look at old forged plane irons from turn of the century infill planes you'll find similarly slightly-off centre stamps, as the production process, with the exception of laser cutting, was very similar.
Having said all of that, I have pulled some samples from stock and couldn't find one that was more than 1/8" off centre, so the bloke with the tongs must be getting very good at it.
MrJay":8fnf94j1 said:
In the interests of accuracy and originality all of our photos are taken specifically for the site, we don't use stock images. For the vast majority of them, the only editing we do is to add the black backgrounds and occasionally tweak the exposure slightly to give a true representation of colours.
MrJay":8fnf94j1 said:
I believe the stamps are applied with a spring hammer to the forged blank. Picture an anvil suspended between two car suspension springs, and a bloke with a big pair of tongs trying to get a 50p sized stamp in exactly the right spot on a slightly less than A4 sized sheet of metal, with uneven edges, at 1000 degrees.
The blades are cut out afterwards with a laser, which is a much more precise operation. However, the blade is lined up with reference to the grain of the steel, not the position of the stamp.
If you look at old forged plane irons from turn of the century infill planes you'll find similarly slightly-off centre stamps, as the production process, with the exception of laser cutting, was very similar.
Having said all of that, I have pulled some samples from stock and couldn't find one that was more than 1/8" off centre, so the bloke with the tongs must be getting very good at it.
