--- product_id: 21156678 title: "Irwin Tools 3016021 Single Cobalt Alloy Steel High-Speed Steel Drill Bit, 21/64\" x 4-5/8\"" brand: "irwin" price: "468513β‚«" currency: VND in_stock: true reviews_count: 13 category: "Irwin" url: https://www.desertcart.vn/products/21156678-irwin-tools-3016021-single-cobalt-alloy-steel-high-speed-steel store_origin: VN region: Vietnam --- # Straight shank for stable, precise drilling 135Β° split-point tip for instant drilling start 8% Cobalt alloy for heat & abrasion resistance Irwin Tools 3016021 Single Cobalt Alloy Steel High-Speed Steel Drill Bit, 21/64" x 4-5/8" **Brand:** irwin **Price:** 468513β‚« **Availability:** βœ… In Stock ## Summary > πŸ”§ Drill like a pro, finish like a boss. ## Quick Answers - **What is this?** Irwin Tools 3016021 Single Cobalt Alloy Steel High-Speed Steel Drill Bit, 21/64" x 4-5/8" by irwin - **How much does it cost?** 468513β‚« with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/21156678-irwin-tools-3016021-single-cobalt-alloy-steel-high-speed-steel) ## 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 - β€’ **Lifetime Confidence:** Backed by a limited lifetime warranty, this drill bit is built to keep up with your toughest projects. - β€’ **Unmatched Durability:** Industrial-grade High-Speed Steel with 8% cobalt alloy resists heat and abrasion for long-lasting performance. - β€’ **Precision Start Every Time:** 135-degree split-point tip eliminates walking and reduces effort, so you drill faster and cleaner. - β€’ **Effortless Tough Metal Drilling:** Designed specifically for heavy-duty abrasive metals and hardened steelβ€”no more slow, frustrating jobs. - β€’ **Perfect Fit for Professional Repairs:** Ideal size for Helicoil thread repair kits and enlarging stainless steel bolt holes with ease. ## Overview The Irwin Tools 3016021 drill bit is a 21/64" x 4-5/8" high-speed steel bit alloyed with 8% cobalt for superior heat and abrasion resistance. Featuring a 135-degree split-point tip and straight shank, it delivers precise, clean holes in tough metals including hardened steel. Trusted by professionals for fast, reliable drilling and backed by a limited lifetime warranty. ## Description Ideal for drilling in tough metal, including heavy-duty abrasive alloy metal drilling on hardened steel. Made from industrial grade High-Speed Steel for increased durability. 8% Cobalt alloy steel is heat and abrasion-resistant. 135-degree split-point tip starts drilling immediately with less force and eliminates "walking" across the work surface. Bit has a straight shank. Review: Great quality - Perfect recommended size to use with a Helicoil 8X1.25mm thread repair kit. Holes are clean (in aluminum) and crisp. Review: Easily enlarged stainless steel header flange bolt hole - Tried using an HSS bit to enlarge a stainless steel header flange bolt hole. Took forever and made bit and flange red hot to get one hole done. This bit enlarged a hole in about 45 seconds. Did the other 4 in just a few minutes. So if you are wondering if you need m35 or m42 cobalt drill for stainless steel, this m35 which is supposed to be 5% cobalt worked great. And 1/3 the price of the m42 cobalt bit. ## Features - Ideal for drilling in tough metal, including heavy-duty abrasive alloy metal drilling on hardened steel - Made from industrial grade High-Speed Steel for increased durability. 8% Cobalt alloy steel is heat and abrasion-resistant - 135-degree split-point tip starts drilling immediately with less force and eliminates "walking" across the work surface - Bit has a straight shank ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000EV382C | | Best Sellers Rank | #37,949 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #90 in Jobber Drill Bits | | Brand Name | IRWIN | | Customer Reviews | 4.6 4.6 out of 5 stars (1,890) | | Cutting Angle String | 135 Degrees | | Cutting Diameter | 0.33 Inches | | Finish Types | Cobalt Alloy Steel | | Global Trade Identification Number | 00024721067104 | | Included Components | 1 cobalt drill bit | | Item Dimensions | 8.5 x 1.9 x 0.3 inches | | Item Type Name | DRILL BIT 21/64 X 4-5/8 COBALT | | Item Weight | 9.07 g | | Manufacturer | IRWIN | | Material Type | Cobalt | | Model | 3016021 | | Number of Flutes | 1 | | Point Style | Split Point | | Shank Type | Straight | | Surface Recommendation | Metal,Steel | | Tool Flute Type | Straight | | UPC | 024721067104 | | Unit Count | 1.0 Count | | Warranty Description | Limited lifetime | ## Product Details - **Cutting Angle String:** 135 Degrees - **Cutting Diameter:** 0.33 Inches - **Finish Type:** Cobalt Alloy Steel - **Material:** Cobalt - **Shank Type:** Straight ## Images ![Irwin Tools 3016021 Single Cobalt Alloy Steel High-Speed Steel Drill Bit, 21/64" x 4-5/8" - Image 1](https://m.media-amazon.com/images/I/319aZN6y6eL.jpg) ## Available Options This product comes in different **Size, Style** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great quality *by L***S on December 30, 2025* Perfect recommended size to use with a Helicoil 8X1.25mm thread repair kit. Holes are clean (in aluminum) and crisp. ### ⭐⭐⭐⭐⭐ Easily enlarged stainless steel header flange bolt hole *by K***A on May 3, 2025* Tried using an HSS bit to enlarge a stainless steel header flange bolt hole. Took forever and made bit and flange red hot to get one hole done. This bit enlarged a hole in about 45 seconds. Did the other 4 in just a few minutes. So if you are wondering if you need m35 or m42 cobalt drill for stainless steel, this m35 which is supposed to be 5% cobalt worked great. And 1/3 the price of the m42 cobalt bit. ### ⭐⭐⭐⭐⭐ Good drill bit *by J***D on March 30, 2026* It drilled a smooth accurate hole in my metal project and didn't show any signs of dulling. What more can I say? --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.vn/products/21156678-irwin-tools-3016021-single-cobalt-alloy-steel-high-speed-steel](https://www.desertcart.vn/products/21156678-irwin-tools-3016021-single-cobalt-alloy-steel-high-speed-steel) --- *Product available on Desertcart Vietnam* *Store origin: VN* *Last updated: 2026-05-16*