| B | SK | PERFORMING OPERATIONS; TRANSPORTING |
| B28 | KL | WORKING CEMENT, CLAY, OR STONE |
| B28D | UKL | WORKING STONE OR STONE-LIKE MATERIALS (machinery for, or methods of, mining or quarrying E21C) |
| B28D 1/00 | HGR | Working stone or stone-like materials, e.g. brick, concrete, not provided for elsewhere; Machines, devices, tools therefor (fine working of gems, jewels, crystals B28D 5/00; working by grinding or polishing B24; devices or means for dressing or conditioning abrasive surfaces B24B 53/00) |
| B28D 1/02 | UGR1 | |
| B28D 1/04 | UGR2 | | . . | with circular saw blades or saw discs (B28D 1/10 takes precedence) |
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| B28D 1/06 | UGR2 | | . . | with reciprocating saw blades (B28D 1/10 takes precedence) |
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| B28D 1/08 | UGR2 | | . . | with saw blades of endless cutter-type, e.g. chain saws, strap saws (B28D 1/10 takes precedence) |
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| B28D 1/10 | UGR2 | | . . | with provision for measuring |
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| B28D 1/12 | UGR2 | | . . | Saw blades specially adapted for working stone |
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| B28D 1/14 | UGR1 | | . | by boring or drilling (rotary drilling machines B23B; percussive tools B25D; earth or rock drilling E21B) [1, 7] |
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| B28D 1/16 | UGR1 | |
| B28D 1/18 | UGR1 | | . | by milling, e.g. channelling by means of milling tools |
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| B28D 1/20 | UGR1 | | . | by planing, e.g. channeling by means of planing tools |
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| B28D 1/22 | UGR1 | | . | by cutting, e.g. incising |
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| B28D 1/24 | UGR2 | |
| B28D 1/26 | UGR1 | | . | by impact tools, e.g. by chisels or other tools having a cutting edge (portable percussive machines B25D) |
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| B28D 1/28 | UGR2 | |
| B28D 1/30 | UGR1 | | . | to form contours, i.e. curved surfaces, irrespective of the method of working used (for artistic purposes B44B) |
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| B28D 1/32 | UGR1 | | . | Methods or apparatus specially adapted for working materials which can easily be split, e.g. mica, slate, schist |
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| B28D 3/00 | HGR | Dressing mill discs or rollers (dressing the tools of sawing machines or sawing devices B23D 63/00; treating the cutting members of cutting machines to facilitate cutting B26D 7/08) |
| B28D 3/02 | UGR1 | |
| B28D 3/04 | UGR2 | |
| B28D 5/00 | HGR | Fine working of gems, jewels, crystals, e.g. of semiconductor material; Apparatus therefor (working by grinding or polishing B24; for artistic purposes B44B; by non-mechanical methods C04B 41/00; non-mechanical after-treatment of single crystals C30B 33/00) [3] |
| B28D 5/02 | UGR1 | | . | by rotary tools, e.g. drills |
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| B28D 5/04 | UGR1 | | . | by tools other than of rotary type, e.g. reciprocating tools |
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| B28D 7/00 | HGR | Accessories specially adapted for use with machines or devices of the preceding groups |
| B28D 7/02 | UGR1 | | . | for removing or laying dust, e.g. by spraying liquids; for cooling work |
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| B28D 7/04 | UGR1 | | . | for supporting or holding work |
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