Laminated plane irons – Stanley and Record

Following the previous articles about iron, steel and plane cutters it may be tempting to view laminated cutters as an historical curiosity from a forgotten era of wooden planes, wrought iron and crucible steel.
However, modern manufacturing companies like Record and Stanley chose to use laminated irons in their metal planes right up until the 1950s.
it is often difficult to tell if a cutter is laminated or not, however the higher carbon content of the steel bit used for the cutting edge can cause it to tarnish when exposed to certain chemicals.  In this case the blade has been dunked in a proprietary rust remover and the high carbon steel bit has turned black.
the joint between the two metal part is just visible as a thin silver line showing on the bevel.

What motivated them?  Cost would still have been a factor, of course,  as it was for the older manufacturers of traditional tapered irons.  And indeed the argument about material cost savings still holds.

Indeed, since both companies were making Bailey-style planes that used much thinner cutters that those found in the wooden planes that had predominated in the previous century, the material cost calculation ought to have been more pressing given the expensive metal needed to form the cutting edge represented a larger proportion of each blade.

Both companies continued to insist on using crucible steel to form the important part of the cutters.   As we have seen, the methods used to create this type of steel were much less efficient than the mass production processes that made the mild steel used for the remainder of the cutter, so we can assume the difference in price between the two metals remained significant.

Having said all that, the material cost savings have to be balanced against the additional manufacturing costs needed to weld and form the two parts into a single piece and the fact that Stanley and Record did – eventually – abandon the practice of laminating their cutters.

How they were made

A clue can be found in this 1937 flyer produced by Stanley:

 

…which says

Both parts, (A and B) are welded together when cast in the ingot and positively cannot be separated

This refers to a process called ‘casting on’ where the harder metal part is placed in a mould and the backing softer metal cast on to it.  We also learn from the flyer that the blades were made by a Sheffield steel maker who would presumably would also have arranged for the laminated material to be rolled and cut or stamped out before being sent to Stanley for heat treatment and grinding.

Record

Record also produced laminated irons and refer indirectly to the same in their promotional book, Planecraft, which was first published in 1934:

Steel facings on iron backs are now standard practise…
Record introduced their bench planes in the early 1930s and, since they were near identical copies of Stanley’s version, it is probable that Record simply copied Stanley’s decision to use laminated cutters and saw no need to advertise the fact.

Why bother?

Stanley’s slightly apologetic flyer does highlight at least one genuine benefit to the user of a laminated cutter, namely that they will spend less time sharpening since there is less of the harder metal to remove.

Of course this  benefit would have been more apparent for users of old tapered irons which were considerably thicker and thus required more metal to be removed at each sharpening.  Indeed it could be argued that the benefit when translated to a much thinner cutter is so slight as to be of little relevance to most users (particularly those people using a mechanical grinder), but it is a benefit nonetheless.

Similarly, although harder to prove, the theoretical advantage that the flexible mild steel backing afforded when hardening the steel bit might have allowed Stanley and Record to produce cutters that held an edge longer than would otherwise be possible1)although they would still have to content with the usual trade-offs – hardening the cutting bit increases wear resistance but reduces strength (that is, makes it more brittle) which can be problematic for something that will occasional collide with the hard knots found in much timber.

Given the marginal benefits to the end user, my theory – and it is little more than a hunch – is that there were  elements of tradition and marketing behind Stanley’s decision to continue to use expensive crucible steel and, so long as they did, it simply made financial sense to use laminated cutters.

Stanley were still advertising their laminated cutters int he 1940s:

 

Popular Mechanics  April 1946

 

.. and seem to have discontinued them in the late 1950s.  An advert in Education 114 (1959) says:

the new Stanley cutter is made of Nickel Chrome Alloy Steel throughout (the old-fashioned composite steel has been discontinued)

As we saw earlier, the handful of operational crucible furnaces that remained open during the 1950s all closed before the end of the decade, and it is likely that Stanley simply lost access to a supply of laminated crucible steel cutters at this point and had to switch to an alternative.

Were Stanley putting a brave face on it when they dismissed the laminated cutters as ‘old fashioned’?  Probably not: the technology to make modern steel alloys was progressing at a pace and it was inevitable that at some point the modern techniques would surpass the abilities of the crucible steel makers who relied so heavily on skill, experience and good judgement to sustain the quality of their product.

We can’t date the Record switch to solid steel cutters precisely either, although a bit of research done by participants on the ukworkshop forum concluded that every ‘square shouldered’ record cutter in our collections was laminated2)see the discussion here : https://www.ukworkshop.co.uk/forums/record-stanley-laminated-plane-irons-t106851.html.

David Lynch’s research concluded that this profile of cutter was in production until the mid 1950s 3)http://www.recordhandplanes.com/dating.html so we can hypothesise that Record switched around the same time as Stanley.   And so ended the mainstream production of laminated plane irons4)this is true in the West at least.  There is still a tradition for laminated tools in Japan, and laminated chisels and plane irons are still made there.

 

square shouldered Record iron – (almost) certainly laminated

 

 

References   [ + ]

1. although they would still have to content with the usual trade-offs – hardening the cutting bit increases wear resistance but reduces strength (that is, makes it more brittle) which can be problematic for something that will occasional collide with the hard knots found in much timber
2. see the discussion here : https://www.ukworkshop.co.uk/forums/record-stanley-laminated-plane-irons-t106851.html
3. http://www.recordhandplanes.com/dating.html
4. this is true in the West at least.  There is still a tradition for laminated tools in Japan, and laminated chisels and plane irons are still made there

1 thought on “Laminated plane irons – Stanley and Record”

  1. I find Stanley’s claim that the steel is cast in the ingot difficult to believe – adding one type of steel to another in the molten state would merely mean the two intermingled and formed an alloy of the two types… It is possible they had one side of the ingot mould lined with a solid sheet of one type before casting the second one on top, but again the rolling process would distort the interface…. I think it is more likely they welded the two steels in the sold state, using a forge welding technique, and then finally rolled to section before slitting and shearing to size…. Scythe makers made their own composite steels, so the technique was ell known in Sheffield…. Many edge tool makers also used a laminate steel, with a hard high carbon steel sandwiched between two layers of a low carbon steel…

Leave a comment