Use a 3/16-inch twist drill bit to drill a blind hole
, 2 to 3 inches deep, in the center of the rounded face.
A hole that doesn't pass all of the way through the barrel is termed a blind hole
. Be certain the original hole has been drilled deep enough to allow a scant section at the bottom to allow for a few metal chips.
If the bolt is in a blind hole
(threaded into a tapped hole instead of a nut on the other side), cheater bars are a dangerous game.
In the Polymer80 lower, the bolt catch pin must be inserted into a blind hole
. The pin supplied with the lower is a 5/64" solid pin that is dropped into the hole and the open end is plugged with a tiny set screw.
In VDI tool holder there is reamed blind hole
. Before reaming it is necessary to make few technologies, it means produce hole for reaming.
The thread mill can also place threads closer to the bottom of a blind hole
, while more room is available for chips to fall away, thus aiding machine uptime by avoiding the entanglement of swarf around the tool.
A bottom tap features almost no taper at all, and is intended to cut threads almost all the way to the bottom of a blind hole
. A plug tap splits the difference between the two and has some taper to the cutting edges.
The MAS features a direct-impingement design in which a puff of gas is delivered from the gas tube into a small blind hole
in the bolt carrier.
"It's a blind hole
so you can't see your tee shot and there are two tree copses either side so people get lost in there.
It should also be noted that mechanical drilling technology has advanced in the area of blind hole
He added: "Regrettably he got trapped in what local fishermen call a blind hole
in the river and he wasn't able to free his feet from the mud.