BS EN ISO 7787‑2:2020 pdf download.Dentistry – Laboratory cutters.
6.3.2 Shank
The shank of laboratory cutters shall be Type 2 as specified in ISO 1797.
The combined length of shank and neck shall be (38 ± 2) mm.
6.4 Cutter blades
The cutter blades of laboratory cutters in Figures 1 to 11 are shown as examples only. The selection of cutter blades is left to the discretion of the manufacturer.
For the designation of cutter blades, see Clause 9 and Table A.1.
Testing shall be carried out in accordance with 8.3.
6.5 Run‑out
The total indicated run‑out shall not exceed 0,08 mm.
Testing shall be carried out in accordance with 8.4.
7 Sampling
Take 10 instruments at random from the validation batch and test them according to the methods described in Clause 8.
This test is intended as type test and not as a routine test, for example, for production batch control.
8 Measurement and test methods
8.1 Shapes
Determine the shapes of laboratory cutters by using a shadowgraph or by measuring the relevant
dimensions in accordance with ISO 8325.
8.2 Dimensions and number of blades
Measure the dimensions in accordance with ISO 8325.
Determine the number of blades by visual inspection.
8.3 Cutter blades
Determine the type of cutter blades by visual inspection.
8.4 Run‑out
Determine the run‑out in accordance with ISO 8325.
The measurement point shall be at the largest diameter or, for cylindrical cutters, the middle of the working part.
8.5 Pass/fail evaluation
If 10 laboratory cutters pass, the product complies.
If eight or fewer laboratory cutters pass, the product fails.
9 Designation
9.1 Designation code numbers
The designation code numbers for carbide laboratory cutters shall be in accordance with ISO 2157.
9.2 Designation of cutter blades
The cutter blades shall be designated by any of the following information, or any combination thereof:
a) a descriptive term such as fine and coarse – more examples are given in Table A.1;
b) its abbreviation such F and C – more examples are given in Table A.1.
The colour code complements the designation. Usage of the colour code for medium cutter blades is optional and at the discretion of the manufacturer.
If colour code is used, the colours shall be those specified in Table A.1.
The location on the instrument where the colour is applied may be on the shank or neck and is left at the discretion of the manufacturer.
10 Marking on the instrument
Marking on the carbide laboratory cutters may contain information concerning the cutter blades.
If a marking is applied, it shall follow the specifications of Clause 9.
Marking by colour shall be applied behind the working part. The location of the marking should be outside of the fitting length. If the marking is applied within the fitting length, the outside diameter of the shank with the marking shall not exceed the effective diameter of the shank.BS EN ISO 7787‑2 pdf download.