---
product_id: 10947961
title: "Tools IRWIN Step Drill Bit, 3/16-Inch to 7/8-Inch, 3/8-Inch Shank (10234)"
brand: "irwin"
price: "Bs.1084"
currency: BOB
in_stock: true
reviews_count: 8
category: "Irwin"
url: https://www.desertcart.bo/products/10947961-tools-irwin-step-drill-bit-3-16-inch-to-7
store_origin: BO
region: Bolivia
---

# 3-flatted hex shank anti-slip Heat-treated molybdenum steel 12-step sizes 3/16" to 7/8" Tools IRWIN Step Drill Bit, 3/16-Inch to 7/8-Inch, 3/8-Inch Shank (10234)

**Brand:** irwin
**Price:** Bs.1084
**Availability:** ✅ In Stock

## Summary

> ⚡ Drill smarter, not harder — the only bit your toolbox will ever need!

## Quick Answers

- **What is this?** Tools IRWIN Step Drill Bit, 3/16-Inch to 7/8-Inch, 3/8-Inch Shank (10234) by irwin
- **How much does it cost?** Bs.1084 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.bo](https://www.desertcart.bo/products/10947961-tools-irwin-step-drill-bit-3-16-inch-to-7)

## Best For

- irwin enthusiasts

## Why This Product

- Trusted irwin brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built to Outlast:** Industrial-grade molybdenum steel with heat treatment for unmatched durability and longevity.
- • **No Slip, No Skid:** 3-flatted hex shank and SpeedPoint tip ensure faster penetration and zero walking.
- • **Lifetime Confidence:** Backed by a full lifetime warranty — invest once, drill forever.
- • **Versatile Material Master:** Perfectly drills stainless steel, brass, aluminum, plastic, and laminates with ease.
- • **One Bit, Endless Precision:** 12 incremental hole sizes eliminate drill swaps and speed up your workflow.

## Overview

The Irwin 10234 Step Drill Bit offers 12 precise hole sizes from 3/16" to 7/8" in 1/16" increments, crafted from heat-treated industrial molybdenum steel for superior durability. Featuring a SpeedPoint tip to prevent walking and a 3-flatted hex shank to eliminate slipping, it effortlessly drills through thin metals and plastics. Designed for professionals who demand efficiency and precision, it’s backed by a lifetime warranty, making it a must-have for any serious toolkit.

## Description

Product Description Irwin 10234 Unibit #4 12-Step High Speed Steel 3/8-inch Step Drill Bit, 1/16-inch Steps (3/16- to 7/8-inch) Save time by eliminating the need to change drills when drilling round holes in thin materials. Each smaller size drill also acts as a pilot for the next size. Made from industrial-grade high-speed molybdenum steel heat treated for maximum durability. Ideal for drilling holes into thin materials such as stainless steel, copper, brass, aluminum, plastic and laminates. SpeedPoint tip penetrates faster than previous Unibits and prevents walking. Non-skid tip does away with the need for center punches; 3-faltted hex shank prevents slipping in drill chuck. Drill diameters etched in flute for easy identification.. desertcart.com The Irwin 10234 UniBit #4 12-Step High Speed Steel Fractional Self-Starting Step Drill has a single-flute cutting edge to give you more control and produce true, round holes. Twelve holes range from 3/16 to 7/8 inches, in 1/16-inch increments. A non-skid tip does away with the need for center punches, while the three flatted shanks prevent slipping in the drill chuck. This drill is made from industrial-grade high-speed molybdenum steel heat treated for maximum durability, and it is ideal for work on thinner materials. The multiple steps mean you don't have to have a toolbox with specific size drill bits, and this drill is backed by a full lifetime warranty. From the Manufacturer The #4 UniBit Step Drill has 12 holes--3/16-inch to 7/8-inch hole sizes with increments of 1/16-inch- shank size is 3/8-inch. Each UniBit step drill has an easy-to-sharpen, non-skid tip which eliminates skidding and the need for center punching; the tip gives sure starts even on curved surfaces. The single-fluted cutting edge that you will find on the UniBit step drills helps assure true round holes and allows greater control. They are constructed of industrial grade high speed molybdenum steel and heat treated to assure maximum durability. The UniBit step drill has 3 flatted shanks, which prevents slipping in drill chuck. The multiple steps on each UniBit eliminates the need to maintain a toolbox full of specific size drill bits. Full lifetime warranty--each UniBit step drill is warranted to be free from defects in material and workmanship for the life of the tool, except for damage caused by abuse, misuse, or alteration.

Review: My 3rd Irwin cobalt Unibit - This is the 3rd Irwin cobalt Unibit I've bought over the last few years. (3 various sizes) A quick summary: Irwin tools are dependable and are of very good quality. I know I can get the job done if I'm using an Irwin tool or bit. My last Unibit was used to drill 120 nickel sized holes into stainless steel plating. (about 1/8" thick) (used a drill press). I was in a hurry and didn't use any drilling oil. The Irwin survived that task but reached its limitation which was more than I expected. I bought this particular Irwin 10234CB to drill a 13/16" hole into my Weber 10020 Smokey Joe Silver Charcoal Grill, Black . I wanted to install a 3" River Country (RC-T3W) Adjustable Professional BBQ, Grill, Smoker Thermometer (50 to 550F) (see my photo on product page) and this Unibit did the job effortlessly. (ate through that lid like it was plastic) Irwin Unibits are pretty expensive compared to other brands, but if you want the very best and longevity, definitely get Irwin cobalt bits. *** Don't forget to use drilling oil (or any oil for that matter, even olive oil) to extend the life of your bits.
Review: Drilling guitar endpin jack holes. - I bought this bit as part of my tool kit to drill endpin jack holes in expensive guitars to mount the endpin jacks for internal pickups. Any drill bit will make a hole, but I wanted to make sure the wood on the guitars would be in perfect condition after the hole was drilled. Causing serious damage to a $5,000 guitar can ruin a guy's day, especially if he's the owner of the guitar. Typically, if no prior hole exists, a new 1/4" hole is drilled with a sharp brad point drill bit, followed by a precision tapered reamer from a guitar luthier supply house. However, sometimes a smaller hole already exists where a strap button was screwed in or a tapered end pin was press fit into a tapered hole. Perhaps the tapered endpin was even glued into the tapered hole and can't be removed without drilling. If a strap button had been screwed in, then the screw hole could be filled and a new hole could be drilled as if none had ever existed, followed by the precision reamer to safely bring the hole to its final dimension. On the other hand, this Irwin Unibit could be used to drill a tapered hole, using the strap button screw hole as a pilot hole, followed by the precision reamer to bring the hole to its final dimension. I have used the Unibit for this exact purpose, and it worked beautifully, with no damage to the guitar. If a tapered wooden strap button has been glued in, the button can be carefully sawed off near its base, and the hole can be drilled with a brad point bit and then reamed, just like the situation where no hole ever existed. But no sawing is needed if a punch is used in the center of the wooden end pin, a 1/8" pilot hole is drilled with a normal twist metal bit or a brad point bit, and the the Unibit is used to drill through the strap button and into the guitar. Eventually, as the Unibit goes deeper, a tapered hole is formed that is larger than the strap button, and the button is drilled completely away, leaving only a nicely tapered hole for the precision reamer to follow and finish to final dimension. The Unibit can be used after drilling a pilot hole, without using the precision reamer. If that is done, it is best to stop drilling with the Unibit when it reaches the 15/32" step and then finish the hole with a standard 15/32" metal twist bit that will tend to self-center. Or, the Unibit can be used to fully penetrate the guitar base and end block, leaving a 1/2" hole that is slightly oversized for most endpin jacks, but completely usable. Alternatively, buy the 12mm Unibit, which is 15/32", and the hole will be exactly the right size. The precision reamer from the well-known guitar luthier supply house is strongly recommended, but even just the Unibit will safely do a good job. Do put blue painter's tape where the hole will be drilled to help protect the wood from damage. DON'T use the cheap tapered hand reamers, including the one from Irwin -- they do not make good, concentric holes in wood. I've tried -- and failed miserably. The cobalt Unibit is not necessary. The standard (less expensive) tool steel works well, just not as long as the cobalt. For $10 more, the cobalt seems to be the better deal if it is used often. This is a must have tool in a guitar workshop.

## Features

- Save time because you don't need to change drills for different-sized round holes in thin materials. Each drill acts as a pilot for the next size.
- Made from industrial-grade high-speed molybdenum steel heat treated for maximum durability. SpeedPoint tip penetrates faster and prevents walking.
- Ideal for drilling holes into thin materials such as stainless steel, copper, brass, aluminum, plastic and laminates.
- Non-skid tip, no need for center punches. 3-faltted hex shank prevents drill chuck slipping. Drill diameters etched in flute for easy identification.
- Backed by a full lifetime warranty.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00004THZ0 |
| Best Sellers Rank | #30,424 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #49 in Step Drill Bits #1,244 in Drill Bits |
| Brand | IRWIN |
| Brand Name | IRWIN |
| Customer Reviews | 4.6 out of 5 stars 894 Reviews |
| Finish Type | Black Oxide |
| Finish Types | Black Oxide |
| Global Trade Identification Number | 00038548101040 |
| Included Components | STEP DRILL #4 3/16-7/8" 12 SZ |
| Item Type Name | STEP DRILL #4 3/16-7/8" 12 SZ |
| Item Weight | 0.01 Ounces |
| Manufacturer | IRWIN |
| Material | High Speed Steel (HSS) |
| Material Type | High Speed Steel (HSS) |
| Model | 10234 |
| Number of Flutes | 1 |
| Point Style | Taper Point |
| Shank Type | 3-Flat |
| Surface Recommendation | Aluminum,Brass,Copper,Steel,Wood |
| Tool Flute Type | Spiral |
| UPC | 795092534631 038548101040 752277668864 013317062265 640024790879 785533446074 |
| Unit Count | 1.0 Count |
| Warranty Description | Limited lifetime |

## Product Details

- **Material:** High Speed Steel (HSS)
- **Finish Type:** Black Oxide
- **Shank Type:** 3-Flat
- **Brand:** IRWIN
- **Item dimensions L x W x H:** 3 x 1 x 6.2 inches

## Images

![Tools IRWIN Step Drill Bit, 3/16-Inch to 7/8-Inch, 3/8-Inch Shank (10234) - Image 1](https://m.media-amazon.com/images/I/61qcRUvI8rL.jpg)

## Available Options

This product comes in different **Size, Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ My 3rd Irwin cobalt Unibit
*by J***U on September 13, 2014*

This is the 3rd Irwin cobalt Unibit I've bought over the last few years. (3 various sizes) A quick summary: Irwin tools are dependable and are of very good quality. I know I can get the job done if I'm using an Irwin tool or bit. My last Unibit was used to drill 120 nickel sized holes into stainless steel plating. (about 1/8" thick) (used a drill press). I was in a hurry and didn't use any drilling oil. The Irwin survived that task but reached its limitation which was more than I expected. I bought this particular Irwin 10234CB to drill a 13/16" hole into my Weber 10020 Smokey Joe Silver Charcoal Grill, Black . I wanted to install a 3" River Country (RC-T3W) Adjustable Professional BBQ, Grill, Smoker Thermometer (50 to 550F) (see my photo on product page) and this Unibit did the job effortlessly. (ate through that lid like it was plastic) Irwin Unibits are pretty expensive compared to other brands, but if you want the very best and longevity, definitely get Irwin cobalt bits. *** Don't forget to use drilling oil (or any oil for that matter, even olive oil) to extend the life of your bits.

### ⭐⭐⭐⭐⭐ Drilling guitar endpin jack holes.
*by A***N on June 8, 2015*

I bought this bit as part of my tool kit to drill endpin jack holes in expensive guitars to mount the endpin jacks for internal pickups. Any drill bit will make a hole, but I wanted to make sure the wood on the guitars would be in perfect condition after the hole was drilled. Causing serious damage to a $5,000 guitar can ruin a guy's day, especially if he's the owner of the guitar. Typically, if no prior hole exists, a new 1/4" hole is drilled with a sharp brad point drill bit, followed by a precision tapered reamer from a guitar luthier supply house. However, sometimes a smaller hole already exists where a strap button was screwed in or a tapered end pin was press fit into a tapered hole. Perhaps the tapered endpin was even glued into the tapered hole and can't be removed without drilling. If a strap button had been screwed in, then the screw hole could be filled and a new hole could be drilled as if none had ever existed, followed by the precision reamer to safely bring the hole to its final dimension. On the other hand, this Irwin Unibit could be used to drill a tapered hole, using the strap button screw hole as a pilot hole, followed by the precision reamer to bring the hole to its final dimension. I have used the Unibit for this exact purpose, and it worked beautifully, with no damage to the guitar. If a tapered wooden strap button has been glued in, the button can be carefully sawed off near its base, and the hole can be drilled with a brad point bit and then reamed, just like the situation where no hole ever existed. But no sawing is needed if a punch is used in the center of the wooden end pin, a 1/8" pilot hole is drilled with a normal twist metal bit or a brad point bit, and the the Unibit is used to drill through the strap button and into the guitar. Eventually, as the Unibit goes deeper, a tapered hole is formed that is larger than the strap button, and the button is drilled completely away, leaving only a nicely tapered hole for the precision reamer to follow and finish to final dimension. The Unibit can be used after drilling a pilot hole, without using the precision reamer. If that is done, it is best to stop drilling with the Unibit when it reaches the 15/32" step and then finish the hole with a standard 15/32" metal twist bit that will tend to self-center. Or, the Unibit can be used to fully penetrate the guitar base and end block, leaving a 1/2" hole that is slightly oversized for most endpin jacks, but completely usable. Alternatively, buy the 12mm Unibit, which is 15/32", and the hole will be exactly the right size. The precision reamer from the well-known guitar luthier supply house is strongly recommended, but even just the Unibit will safely do a good job. Do put blue painter's tape where the hole will be drilled to help protect the wood from damage. DON'T use the cheap tapered hand reamers, including the one from Irwin -- they do not make good, concentric holes in wood. I've tried -- and failed miserably. The cobalt Unibit is not necessary. The standard (less expensive) tool steel works well, just not as long as the cobalt. For $10 more, the cobalt seems to be the better deal if it is used often. This is a must have tool in a guitar workshop.

### ⭐⭐⭐⭐⭐ Nice, clean, perfect holes
*by A***D on September 14, 2012*

I needed to make larger holes in steel sheet metal. Traditional drill bits bind up in the hole when you get close to fully drilling through the hole. Adjustable circle hole cutters and expanding bits can be dangerous if used free hand, and sometimes even used in the drill press. All of these types can twist your wrist badly if you are using them free hand. I decided to try this step bit and see how they worked. It was fantastic! I drilled a large enough pilot hole with a twist bit, and then started feeding the step bit in the hole. It cut smoothly and did not bind up at all. The hole it made was perfectly round and no burs left on the front side. It did leave burs on the backside of the metal, but I simply did a very light drill with this step bit on the back just enough to knock off the burs. Presto...a clean wonderful hole was drilled quickly. I am now a true believer in step bits. This bit also kept its edge very well. I highly recommend this product.

## Frequently Bought Together

- Irwin Tools IRWIN Step Drill Bit, 3/16-Inch to 7/8-Inch, 3/8-Inch Shank (10234)
- Irwin Tools IRWIN Step Drill Bit, 1/8-Inch to 1/2-Inch Step, 1/4-Inch Shank (10231) Silver|Silver metallic
- Jerax tools 3/16-7/8 Inch Step Drill Bit, M2 HSS Spiral Grooved Step Bit for Stainless Steel, Metal, Wood, Plastic

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*Product available on Desertcart Bolivia*
*Store origin: BO*
*Last updated: 2026-02-26*