US 2340383 A
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Patented Feb. 1, 1944 LAPPING TOOL Foster F. Hillix, Lakewood, Ohio, assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey No Drawing. Original application April 10, 1939,
Serial No. 267,127.
This invention relates to lapping tools and the like, and to compositions therefor, this application being a division of my pending application Serial No. 267,127, filed April 10, 1939.
My invention contemplates a lapping tool particularly adapted for use as a roughing lap with suitable granular abrasive to initiate the finishing operation upon hard objects such as metal-working rolls and the like.
Divided and this application August 15, 1942, Serial No. 454,992
This lap is used to best advantage with abrasive grain from 240-600 mesh.
The desirable characteristics attributable to the metals specified are those which will provide sufficient mechanical strength to enable the grain to cut, and yet, which will be soft enough to charge with abrasives, and sufficiently granular to wear away so as to obviat bunching or seizing of the cuttings and abrasive grains; and
I have discovered that a lapping tool composed 10 which will also provide a surface of the requisite of a friable metal composition produces highly porosity to receive the latter in order that they satisfactory results for the purpose stated, and may be retired harmlessly from pressure contact that antimonial lead of substantially the followwith the surface of the work. in proportions is particularly suitable for such Various changes and modifications are contema roughing lap when molded into block form: 15 plated within the scope of the following claim.
Per cent by weight Lead 65 Antimony 35 This material is brittle and is hard enough to withstand suflicient pressure to make the coarser grains cut, but wears away fast enough to prevent the material from bunching on the face of the lap and producing streaks on the roll.
A roughing lap comprising a friable composition of substantially 65 per cent lead and 35 per cent antimony, by weight, molded into block 2 form, characterized by having suificient strength