Countersinks, Reamers & Burs

500+ products

Expected delivery: Wed, Nov 18

These tools finish a hole or edge after drilling. Countersinks cut a cone so flat head screws sit flush and also break sharp edges. Reamers bring a drilled hole to an exact size with a smooth finish for pins, bushings and shafts. Carbide burs shape, deburr and port metal in a die grinder. This section includes single flute, multi-flute and zero flute countersinks, chucking reamers, hand reamers and adjustable reamers, carbide burs in common shapes and cuts, and hand deburring tools.

What to check before you order

• Countersink angle. Match the screw head. Inch flat head screws generally use 82 degrees, metric flat heads use 90 degrees, and some aircraft fasteners use 100 degrees.
• Reamer allowance. Drill the hole slightly under the finished size before reaming. Reamers remove only a small amount of stock.
• Bur shape and cut. Cylinder, ball, tree and flame shapes reach different areas. Double cut burs leave smaller chips and a smoother finish on steel. Single cut suits hard steel and general stock removal.
• Shank and speed. Most burs have a 1/4" or 1/8" shank. Stay within the bur maker's speed rating and wear eye protection.

Browse drill bits, end mills and inserts, Alfa Tool countersinks and reamers, or all cutting tools.

Common questions

What is the difference between a chucking reamer and a hand reamer?

A chucking reamer runs in a drill press, lathe or mill at reduced speed. A hand reamer has a square end for a tap wrench and a longer tapered lead so it can start straight by hand.

Can carbide burs be used on aluminum?

Yes, but standard cuts can clog with soft metal. Aluminum-cut burs have coarse, widely spaced flutes that clear chips better on nonferrous metals. Follow the bur maker's speed guidance and wear eye protection.

Countersinks, Reamers & Burs: page 11

• Approved Vendor 7/32" X 3/32" Pilots for Counterbore SKU 29042 $8.04
• Approved Vendor 7/32" X 5/32" Pilots for Counterbore SKU 29039 $8.04
• Approved Vendor 7/8" HSS 3MT Straight Flute Bridge Reamer SKU 28994 $88.71
• Approved Vendor 7/8" HSS Straight Flute Hand Expansion Reamer SKU 31727 $238.63
• Approved Vendor 7/8" HSS Straight Flute Hand Reamer SKU 31726 $79.02
• Approved Vendor 7/8" HSS Straight Shank Machine Expansion Reamer SKU 31722 $119.13
• Approved Vendor 7/8" HSS Taper Shank Machine Expansion Reamer SKU 31719 $129.08
• Approved Vendor 7/8" X 1/2" Pilots for Counterbore SKU 29017 $20.09
• Approved Vendor 7/8" X 1/4" Pilot Hole HSS Straight Shank Counterbore SKU 29009 $56.97
• Approved Vendor 7/8" X 1/4" Pilot Hole HSS Taper Shank Counterbore SKU 29001 $58.69
• Approved Vendor 7/8" X 1/4" Pilots for Counterbore SKU 29019 $20.09
• Approved Vendor 7/8" X 3/16" HSS Aircraft Counterbore 1/4" Shank SKU 29045 $64.12
• Approved Vendor 7/8" X 3/8" Pilots for Counterbore SKU 29021 $20.09
• Approved Vendor 7/8" X 5/16" Pilots for Counterbore SKU 29018 $20.09
• Approved Vendor 7/8" X 7/16" Pilots for Counterbore SKU 29020 $20.09
• Approved Vendor 7/8"-100 HSS Single Flute Countersink SKU 29106 $47.98
• Approved Vendor 7/8"-120 HSS Single Flute Countersink SKU 29105 $47.98
• Approved Vendor 7/8"-60 HSS Single Flute Countersink SKU 29109 $47.98
• Approved Vendor 7/8"-82 HSS Single Flute Countersink SKU 29108 $47.98
• Approved Vendor 7/8"-90 HSS Single Flute Countersink SKU 29107 $47.98
• Approved Vendor 7/A HSS Adjustable Reamer 9/32" - 5/16" SKU 31015 $40.28
• Approved Vendor 8/A HSS Adjustable Reamer 1/4" - 9/32" SKU 31013 $40.28
• Approved Vendor 9/16" HSS 2MT Straight Flute Bridge Reamer SKU 28995 $48.03
• Approved Vendor 9/16" HSS Straight Flute Hand Expansion Reamer SKU 31729 $168.42
• Approved Vendor 9/16" HSS Straight Flute Hand Reamer SKU 31711 $53.47
• Approved Vendor 9/16" HSS Straight Shank Machine Expansion Reamer SKU 31725 $86.64
• Approved Vendor 9/16" HSS Taper Shank Machine Expansion Reamer SKU 31720 $91.39
• Approved Vendor 9/16" X 1/2" Pilots for Counterbore SKU 29024 $12.39
• Approved Vendor 9/16" X 1/4" Pilots for Counterbore SKU 29026 $12.39
• Approved Vendor 9/16" X 1/8" HSS Aircraft Counterbore 1/4" Shank SKU 29046 $48.82
• Approved Vendor 9/16" X 3/16" Pilot Hole HSS Straight Shank Counterbore SKU 29012 $43.36
• Approved Vendor 9/16" X 3/16" Pilot Hole HSS Taper Shank Counterbore SKU 29002 $43.71
• Approved Vendor 9/16" X 3/16" Pilots for Counterbore SKU 29022 $12.39
• Approved Vendor 9/16" X 3/8" Pilots for Counterbore SKU 29027 $12.39
• Approved Vendor 9/16" X 5/16" Pilots for Counterbore SKU 29025 $12.39
• Approved Vendor 9/16" X 7/16" Pilots for Counterbore SKU 29023 $12.39
• Approved Vendor 9/32" HSS Straight Flute Hand Expansion Reamer SKU 31730 $127.78
• Approved Vendor 9/32" HSS Straight Flute Hand Reamer SKU 31714 $32.40
• Approved Vendor 9/32" X 1/8" Pilots for Counterbore SKU 29038 $8.65
• Approved Vendor 9/32" X 3/16" Pilots for Counterbore SKU 29035 $8.65
• Approved Vendor 9/32" X 3/32" HSS Aircraft Counterbore 1/4" Shank SKU 29047 $36.68
• Approved Vendor 9/32" X 3/32" Pilot Hole HSS Straight Shank Counterbore SKU 29014 $33.20
• Approved Vendor 9/32" X 3/32" Pilot Hole HSS Taper Shank Counterbore SKU 29004 $34.83
• Approved Vendor 9/32" X 3/32" Pilots for Counterbore SKU 29036 $8.65
• Approved Vendor 9/32" X 5/32" Pilots for Counterbore SKU 29037 $8.65
• Approved Vendor A HSS Adjustable Reamer 15/32" - 17/32" SKU 31008 $43.80
• Alfa Tool Asa # 1 x 3 HSS Combined Drill & Countersink SKU CD50471 $9.78
• Alfa Tool Asa # 1 x 4 HSS Combined Drill & Countersink SKU CD50472 $10.26

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