{"product_id":"drill-america-4-cobalt-heavy-duty-drill-bit-pack-of-12-durable","title":"Drill America #4 Cobalt Heavy Duty Drill Bit Pack of 12 - Durable","description":"\u003cp\u003eIn this review the Drill America #4 Cobalt Heavy Duty Drill Bit (Pack of 12) is judged as a workhorse set for machinists and tradespeople who need reliable performance when cutting tough metals. The bottom line: it is best for users who regularly drill stainless steel, nickel alloys or other high tensile materials because the cobalt steel formulation holds heat and hardness under heavier cutting loads. The pack of 12 offers good value for shops and hobbyists who prefer jobber length bits that combine durability with versatility.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCobalt steel construction:\u003c\/strong\u003e Provides improved red hardness so the bits maintain cutting edge and can run hotter than standard high-speed steel when drilling hard alloys.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGold oxide finish:\u003c\/strong\u003e A thinner surface treatment that identifies the tool and offers corrosion resistance without changing cutting behavior compared with uncoated bits.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpiral fluted right-hand cut:\u003c\/strong\u003e Evacuates chips up and out of holes to reduce clogging and keep holes cleaner during continuous work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRound shank design:\u003c\/strong\u003e Fits a wide variety of chucks and toolholding systems for easy switching between handheld drills and drill presses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufactured to NAS 907:\u003c\/strong\u003e Built to a recognized aerospace standard, indicating consistent geometry and quality suitable for demanding applications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis set is aimed at metalworkers, mechanics, and serious DIYers who frequently drill high tensile materials like PH stainless, inconel or titanium and need bits that hold hardness and cut reliably under higher speeds. The twelve-piece pack suits small shops or individuals who want backups and repeatable performance without purchasing single specialty bits.\u003c\/p\u003e\n\u003cp\u003eThose who primarily drill soft materials, wood, or occasional light-duty metal might look elsewhere for cheaper carbon or HSS options, and users needing carbide performance for production CNC work should consider solid carbide tools rather than jobber-length cobalt bits.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eExcellent durability and edge retention in hard metals thanks to the cobalt alloy.\u003c\/li\u003e\n\u003cli\u003eGood value for money when buying a 12-piece pack for shop rotation and replacements.\u003c\/li\u003e\n\u003cli\u003eThin gold oxide finish provides basic protection while keeping cutting action similar to uncoated bits.\u003c\/li\u003e\n\u003cli\u003eRound shanks and standard jobber length make these bits versatile across machines.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot coated with thicker performance coatings, so users wanting extreme wear resistance may prefer other surface treatments.\u003c\/li\u003e\n\u003cli\u003eAngle feedback in reviews is mixed, so hole entry geometry may vary slightly between pieces.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries\u003c\/td\u003e\n\u003ctd\u003eD\/ACO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eCobalt steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish\u003c\/td\u003e\n\u003ctd\u003eGold oxide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShank type\u003c\/td\u003e\n\u003ctd\u003eRound shank\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003eJobber length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturing standard\u003c\/td\u003e\n\u003ctd\u003eNational Aerospace Standard 907\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePack quantity\u003c\/td\u003e\n\u003ctd\u003e12 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Drill America #4 Cobalt Heavy Duty Drill Bit pack is a practical, cost-effective choice for anyone who needs dependable drilling in tough alloys; its cobalt build and jobber length deliver long life and versatility in workshop settings, making it a smart buy for metalworkers who value durability and predictable performance.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eAre these bits good for stainless steel?\u003c\/strong\u003e\u003cbr\u003eYes, the cobalt alloy and higher red hardness make them well suited for drilling stainless steel and other high tensile materials.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill the gold oxide change cutting performance?\u003c\/strong\u003e\u003cbr\u003eNo, the gold oxide is a thin surface treatment that mainly aids identification and basic corrosion resistance without altering cutting behavior.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan these bits be used in a hand drill?\u003c\/strong\u003e\u003cbr\u003eYes, the round shank and jobber length allow use in a wide variety of chucks and handheld drills as well as drill presses.\u003c\/p\u003e","brand":"Drill America","offers":[{"title":"Default Title","offer_id":48249955418331,"sku":"B00FX6URWC","price":38.41,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/71bfcGlQTwL._SL1500_8bde4896-5087-43b3-8c47-cca0c202589b.jpg?v=1771089752","url":"https:\/\/gearmusthave.com\/products\/drill-america-4-cobalt-heavy-duty-drill-bit-pack-of-12-durable","provider":"GearMustHave","version":"1.0","type":"link"}