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Super Cobalt Drill #21

$2.85/Piece
Part# 12-14221
MFR Model# 5270021
DescriptionDrill SizeApprox
Length
Part Number
Super Cobalt Drill #21213-5/16"12-14221

Overview

These super cobalt hi-speed jobber length aircraft drill bits feature heavy duty construction to Type J aircraft specifications. Use to drill hard, tough metals, stainless steels, iron based and titanium alloys, and certain plastics. Hardness of cobalt permits speeds 30% over regular H.S.S. drills. Cobalt drills demand rigidly held, positive feed drilling equipment.
   
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WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.

Reviews

Patrick R Verified Purchase

Super Cobalt Drill #21

January 3, 2024

Excellent quality, very sharp and stayed sharp. A couple bits in my 100 piece set are getting dull so I replaced them. Unfortunately Spruce doesnt offer all sizes, they skip some numbers, and larger sizes as well. Sure wish they had a complete selection. Its tough to find single bits from other sources with as reasonable shipping as A/C Spruce.

Brian S
May 17, 2021

Fastest delivery to my address in two (2) days after order!!! Great!

Johan A
May 17, 2021

I am learning to scratch build an airplane. This was a big help learning that process. It takes materials and I have some now :D Excellent condition and they allowed me to come and pick up the stuff myself. Awesome! Great customer service. I had a lot of questions and they did not get upset with me when I changed my mind and decided to go in another direction. They simply supported me and I purchased even more stuff! I have been using this company for decades. I first started with the supplies needed for R/C aircraft back in the 80 and 90s.

Michael
May 6, 2021

I am learning to scratch build an airplane. This was a big help learning that process. It takes materials and I have some now :D Excellent condition and they allowed me to come and pick up the stuff myself. Awesome! Great customer service. I had a lot of questions and they did not get upset with me when I changed my mind and decided to go in another direction. They simply supported me and I purchased even more stuff! I have been using this company for decades. I first started with the supplies needed for R/C aircraft back in the 80 and 90s.

Michael
May 6, 2021

Great drill bits, reasonable price and in stock in Alaska.

Barry S
May 4, 2021

These are very sharp, great drill bits. I wish the size stampings were a little better (some are readable, some are not), but the actual drill bit cutting quality is amazing.

Ray A
April 27, 2021

Great wire size drill bits couldnt be happier.

Guy
March 8, 2021

Nice sharp accurate drill bits.

James W
August 9, 2020

Good so far.

Tom
July 1, 2020

Q&A

Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: What is the length of drill bit part number 12-04212?

The 12-04212 drill bit is 2-1/4" long.

Q: Are these bits 135 degree or 118 degree cut?

They have a 135 degree split.

Q: WHAT IS THE RECOMMENDED DRILL FOR THE AN6-20A BOLT

You would need at least a 3/8 drill.

Q: Which number is the diameter 3/32?

42 would be slightly under and 41 would be slightly over 3/32.

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