What is the difference between Counterboring and countersinking?
A countersink is a cone shaped hole cut into the laminate. It is typically used to allow the tapered head of a screw to sit flush with the top of the laminate. By comparison, a counterbore makes a flat-bottomed hole and its sides are drilled straight down. This is usually used to fit a hex-headed cap or screw.
Fluted countersinks come in several sizes, able to cut conical holes intended to fit screws of varying head dimensions. A pilot hole is first drilled for the screw, followed by countersinking the hole to allow a flathead screw to seat flush with the work surface.
- The second is if you want to hide a screw head, the countersink hole will allow the head of the screw to sink below the material it is inserted into and can then be filled over and painted. To drill a countersink, place the countersink bit in your drill and push down lightly on the pilot hole.
- Uses for Taper Drill Bits. Taper Point Drills were engineered to be used to pre drill the pilot holes for the shank and threaded portion of a wood screw. The object, of course, is to use the proper size drills and drill to the proper depth to insure the best holding power from the wood screw.
- The point angle of a twist drill is the angle made by the cutting lip and the axis of the drill. For general purpose drilling a point angle of 59° (118° included angle) is recommended. The point angle may vary somewhat, one way or the other, but the variation should be uniform in both cutting lips.
A common use is to allow the head of a countersunk bolt, screw or rivet, when placed in the hole, to sit flush with or below the surface of the surrounding material (by comparison, a counterbore makes a flat-bottomed hole that might be used with a socket-head capscrew).
- A counterbore hole is typically used when a fastener, such as a socket head cap screw, is required to sit flush with or below the level of a workpiece's surface. Whereas a counterbore is a flat-bottomed enlargement of a smaller coaxial hole, a countersink is a conical enlargement of such.
- A bugle screw is a form of self-drilling screw that's specifically designed for drywall applications. Bugle head screws feature a countersunk head with a flat top and a concave under-head bearing surface.
- This particular geometry tool leaves a center core of material that can be used for another part. Trepanning is an energy efficient type of hole cutting that removes an annulus (ring shaped) of material without converting the entire center into chips like a drill.
GRK's R4 Self Countersinking screw has six self-contained cutting pockets which act like a router and transport the drill dust away from the edge of the screw hole. They also widen the countersink hole only around the head shape.
- Medication in liquid form is allowed in carry-on bags in excess of 3.4 ounces in reasonable quantities for the flight. TSA does not require passengers to have medications in prescription bottles, but states have individual laws regarding the labeling of prescription medication with which passengers need to comply.
- Do not pack you portable charger (power pack) in hold luggage: Taking your portable phone charger (power pack) on a plane is fine, but just remember to pack it in your hand luggage. Do not put them in your hold luggage as this is not permitted and could result in your luggage not being loaded.
- Liquids and Gels. You may only carry on liquids and gels that are in 3.4-ounce containers or smaller. Liquids include toiletries such as shampoo, after-shave, hand or body lotion, mouthwash and liquid makeup. Toiletries often found in gel form include toothpaste, deodorant and lip balm or lipstick.
Updated: 3rd December 2019