





🔧 Drill Smarter, Not Harder: One Bit to Rule Them All!
The Irwin 10231 Step Drill Bit offers 13 incremental hole sizes from 1/8" to 1/2" in a single high-speed steel bit. Featuring a patented single-flute cutting edge and SpeedPoint tip, it ensures fast, precise drilling with no walking. Its 3-flat hex shank prevents slipping, making it perfect for professionals working with thin metals and plastics who demand efficiency and accuracy.


| ASIN | B00004THYX |
| Best Sellers Rank | #35,826 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #61 in Step Drill Bits |
| Brand | IRWIN |
| Cutting Angle String | 118 Degrees |
| Cutting Diameter | 12.7 Millimeters |
| Date First Available | April 1, 2004 |
| Department | Unisex-Adult |
| Finish Type | Black Oxide |
| Global Trade Identification Number | 00038548101019 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1.44 ounces |
| Item dimensions L x W x H | 6 x 2.87 x 0.75 inches |
| Item model number | 10231 |
| Manufacturer | IRWIN |
| Material | High Speed Steel (HSS) |
| Number of Flutes | 1 |
| Number of Pieces | 1 |
| Point Style | Step Point |
| Product Dimensions | 6 x 2.87 x 0.75 inches |
| Set Name | 1/8" to 1/2" 13 SZ |
| Shank Type | Hex 3-flat |
| Surface Recommendation | Aluminum,Brass,Copper,Metal,Plastic,Stainless Steel,Steel |
| Tool Flute Type | Spiral |
| UPC | 787721839125 780541552908 038548101019 |
| Unit Count | 1.0 Count |
A**V
Great buy
Wonderful bit. It cut through my 2mm aluminum bracket quite easily. Haven't tested on other metals but seems sharp and durable.
R**T
easier than a spade bit
Cuts clean & easy
R**B
You get quality and service life
This is the 3rd Unibit of this size in the last 10 years that I have owned, it is not that it is poorly made, its just that I keep using them. This is the only bit that I have found that I can cut gasket foil, if I do not have a punch that size (requires some trickery). It has many, many uses and I keep finding new ones. I have tried other brands but in this style, of the major brands, this last the longest of the non-impact tapered bits. I have run it at 7,500 rpm without incident and as slow as 2 rpm on 1/8" titanium sheet (prepunched starter hole). The Unibits may seem expensive when compared to HF or other cheap brands but with these you get quality and service life.
J**G
Center punch needed to get it started.
Did the job, drilling holes in steel edging; the thicker, older stuff. I didn't try it on high speed, but low, using lots of 30W oil and it did cut well....once you got it started. Used a center punch to start the holes, but found that they needed to be deeper before the drill point would catch. Once it caught, it was easy going......with pressure :) Pricey, but worth it for my project.
L**E
Fits in my tool bag just great!
Love this step bit , great for impact !
A**1
Great quality and value
It does a clean and professional drill every time and is made of high quality material that doesn’t easily break, also the value was very good
V**.
This is a great tool. Unibit tip
Bottom line? Life would just stink without Unibits (step drills). I bought my first one in about 1995 building race cars. I use them as much everyday as most people use a fork or knife. This is a great tool. Unibit tip: A common complaint of people using step drills is that they forget which "step" they are drilling to and over drill their hole. I always have a sharpie in my pocket. I just color the step I am drilling to with my sharpie. When I get to the "black sharpie" step, I stop, and the metal gets rid of most of the sharpie so I am ready to make a new mark on the next hole. It works for me. Perhaps it will help avoid overdrilling.
M**E
Fast bit
This bit is very aggressive in removing steel. I've never had it hang up and take my wrist for a ride. A small pilot hole lets this bit work alot faster, but is not required. I also like that it's made for an impact driver instead of a drill. I'll be buying more of these as I eventually wear them out or lose them.
L**E
tremendo producto. es una estupenda inversión. tiene una durabilidad increíble.
P**G
Superb highly recommend
A**Y
Cuts through sheet metal with ease. I have used Irwin and I have used Klein unibits. The Irwin bits stay sharper longer.
M**L
It kept wanting to walk even with vise and drill press. Hole is not concentric.
S**N
Le forêt a un embout plat donc il patine sur le metal
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