Counterbored

Workpieces that shall be bolted to one another have to be clamped together and to be drilled and counterbored jointly, so that the alignment of the bore is maintained. ❋ Frank Wenghfer (1990)

(TB = 20.5 mm) diameter of counterbored/countersunk hole: ❋ Unknown (1990)

The workpieces, as far as possible, should be clamped in such way, that they can be drilled, counterbored/countersunk and reamed in succession without the clamping being loosened in between. ❋ Frank Wenghfer (1990)

- A steel body with drilled and counterbored holes has to be clamped into the vice. ❋ Unknown (1990)

The instructor has to stress again that the parts are drilled, counterbored and fixed in the vice while being clamped together. ❋ Unknown (1990)

- A drilled and counterbored steel part must be clamped in the vice. ❋ Unknown (1990)

To make the matter worse, quite a number of the wheels were found to have been counterbored about ½ in. deep at the back end, and the axle turned up to fit this counterbore; a good idea to prevent the running in, in case the wheel worked loose, but bad from the standpoint of a change of gauge. ❋ Various (N/A)

The mud drum to which the sections are attached at the lower end of the rear headers, is a forged-steel box 7¼ inches square, and of such length as to be connected to all headers by means of wrought nipples expanded into counterbored seats. ❋ Unknown (N/A)

The flanges on high pressure lines should be counterbored to receive pipe and prevent the threads from shouldering. ❋ Unknown (N/A)

The upper side of the top block is counterbored to fit the end of the shaft. ❋ Unknown (1902)

The holes can be counterbored for the heads and then plugged. ❋ Unknown (1891)

The front is rough and finish-bored to accept an M55 thread, which is then counterbored and screw cut. ❋ Unknown (2010)

This particular rifle had been counterbored at some point to remove damage at the crown. ❋ Unknown (2009)