{"title":"Counterbores","description":"\u003ch2\u003eCounterbore Selection — Quick Reference\u003c\/h2\u003e\n\u003cp\u003eCounterbores produce FLAT-BOTTOMED RECESSED HOLES allowing SOCKET HEAD CAP SCREWS + similar fasteners to sit FLUSH with or BELOW the surface. Drill press + lathe + machining centre + workshop standard.\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eCounterbore Type\u003c\/th\u003e\n\u003cth\u003eBest For\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandard Counterbore (Pilot)\u003c\/td\u003e\n\u003ctd\u003eSHCS recess — common workshop\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterchangeable Pilot\u003c\/td\u003e\n\u003ctd\u003eMultiple SHCS sizes from one counterbore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCarbide-Tipped Counterbore\u003c\/td\u003e\n\u003ctd\u003eHardened material + production\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHSS Standard\u003c\/td\u003e\n\u003ctd\u003eMild + low-alloy steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpotface Counterbore\u003c\/td\u003e\n\u003ctd\u003eFlat seating surface — no recess\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSet (Workshop Range)\u003c\/td\u003e\n\u003ctd\u003eSHCS M4-M20 typical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eCritical:\u003c\/strong\u003e Pilot diameter MATCHES screw clearance hole (M8 SHCS = 8.5mm pilot + 14mm body counterbore for socket head). SLOW SPEED + cutting fluid. Brands: \u003ca href=\"\/en-nz\/collections\/sutton-tools\"\u003eSutton Tools\u003c\/a\u003e, \u003ca href=\"\/en-nz\/collections\/bordo\"\u003eBordo\u003c\/a\u003e. Companion: \u003ca href=\"\/en-nz\/collections\/countersink-bit-sets\"\u003ecountersink bit sets\u003c\/a\u003e, \u003ca href=\"\/en-nz\/collections\/socket-head-cap-screws\"\u003esocket head cap screws\u003c\/a\u003e, \u003ca href=\"\/en-nz\/collections\/drilling\"\u003edrilling\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eCounterbores\u003c\/h2\u003e\u003cp\u003eCounterbores produce flat-bottomed recessed holes that allow socket head cap screws and similar fasteners to sit flush with or below the surface of the workpiece — essential for assemblies where a projecting fastener head would interfere with mating components, guards or covers. AIMS Industrial stocks HSS counterbores in standard pilot sizes for M3 to M20 socket head cap screws for use in drill presses and milling machines.\u003c\/p\u003e\u003ch3\u003eCounterbore vs Countersink\u003c\/h3\u003e\u003cp\u003eA counterbore produces a flat-bottomed recess with straight sides — used for socket head cap screws (Allen cap screws) and flanged bolts whose heads are cylindrical. A countersink produces an angled (typically 90° or 82°) tapered recess — used for countersunk head (flat head) screws where the tapered head must sit flush. The application determines which is needed: for any fastener with a cylindrical or flanged head that must be recessed below the surface, a counterbore is the correct tool.\u003c\/p\u003e\u003ch3\u003ePilot Pin and Size Selection\u003c\/h3\u003e\u003cp\u003eCounterbores are sized by the outer diameter (matching the cap screw head diameter plus clearance) and the pilot pin diameter (matching the bolt clearance hole diameter). The pilot pin ensures the counterbore is concentric with the pre-drilled clearance hole. Standard counterbore sets cover the common cap screw sizes — M3, M4, M5, M6, M8, M10, M12, M16 and M20 — in pilot diameters to suit standard or close-tolerance clearance holes.\u003c\/p\u003e\u003ch3\u003eMaterial and Use\u003c\/h3\u003e\u003cp\u003eHSS counterbores suit mild steel, cast iron and aluminium for general engineering and maintenance applications. For harder materials or high-volume CNC use, carbide-tipped or solid carbide versions are available. For help selecting the right counterbore size for your fastener and material, \u003ca href=\"\/en-nz\/pages\/contact-us\"\u003econtact our team\u003c\/a\u003e. AIMS Industrial has been supporting Australian workshops since 1988.\u003c\/p\u003e","products":[{"product_id":"sutton-tools-c100-counterbore-din373-cobalt-steel-hss-e","title":"Sutton Tools C100 Counterbore - DIN373 Cobalt Steel HSS-E","description":"\u003cdiv style=\"max-width:680px;width:100%;padding:12px 0;font-family:Arial,sans-serif;\"\u003e\n\u003cdiv style=\"display:flex;align-items:flex-start;justify-content:space-between;border-top:1px solid #e0e0e0;border-bottom:1px solid #e0e0e0;padding:16px 0;margin-bottom:24px;\"\u003e\n\u003cdiv style=\"flex:1;padding:0 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:24px;color:#333;margin-bottom:6px;line-height:1;\"\u003e◆\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:500;color:#333;line-height:1.4;\"\u003e6mm Diameter\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;padding:0 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:24px;color:#333;margin-bottom:6px;line-height:1;\"\u003e●\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:500;color:#333;line-height:1.4;\"\u003eCobalt HSS\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;padding:0 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:24px;color:#333;margin-bottom:6px;line-height:1;\"\u003e▲\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:500;color:#333;line-height:1.4;\"\u003eTiN\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size:14px;line-height:1.6;color:#444;margin:0;\"\u003eA 6mm drill bit in Cobalt HSS, sized for accurate, repeatable holes across general workshop and trade applications.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Sutton Tools","offers":[{"title":"3","offer_id":49274566639893,"sku":"A0002629","price":149.06,"currency_code":"AUD","in_stock":true},{"title":"4","offer_id":49274566672661,"sku":"A0002630","price":137.34,"currency_code":"AUD","in_stock":true},{"title":"5","offer_id":49274566705429,"sku":"A0002631","price":151.19,"currency_code":"AUD","in_stock":true},{"title":"6","offer_id":49274566738197,"sku":"A0002632","price":158.27,"currency_code":"AUD","in_stock":true},{"title":"8","offer_id":49274566770965,"sku":"A0002633","price":265.33,"currency_code":"AUD","in_stock":true},{"title":"10","offer_id":49274566803733,"sku":"A0002634","price":327.06,"currency_code":"AUD","in_stock":true},{"title":"12","offer_id":49274566836501,"sku":"A0002635","price":342.48,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0740\/5191\/1957\/files\/sutton-tools-c100-counterbore-din373-cobalt-steel-hss-e-3499508.jpg?v=1781531429"},{"product_id":"bordo-3870-set-3-10mm-6pieces","title":"Bordo 3870-SET 3 - 10mm, 6pieces","description":"\u003cdiv style=\"max-width:680px;width:100%;padding:12px 0;font-family:Arial,sans-serif\"\u003e\n\u003cdiv style=\"display:grid;grid-template-columns:1fr 1fr 1fr;gap:0;margin-bottom:24px\"\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e◆\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eBright finish HSS-Co5 (Cobalt) for extreme tool life.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e●\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eUse to enlarge the top of an existing hole to create a cylindrical-shaped opening with a flat bottom that acts as a seat for the head of a screw or wood plug.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e▲\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eIdeal for use with standard cap screws or socket head screws.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size:14px;color:#444;line-height:1.7;margin:0\"\u003e6 Pce 3-10mm 180 Degree Counterbore Set. Bright finish HSS-Co5 (Cobalt) for extreme tool life Designed for demanding countersink bit applications. A practical choice for hss drill bits requirements in trade and industrial environments.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Bordo","offers":[{"title":"Default Title","offer_id":49296751919381,"sku":"A0145316","price":815.93,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0740\/5191\/1957\/files\/bordo-3870-set-3-10mm-6pieces-5944327.jpg?v=1781510953"},{"product_id":"bordo-3871-set-3-10mm-6pieces","title":"Bordo 3871-SET 3 - 10mm, 6pieces","description":"\u003cdiv style=\"max-width:680px;width:100%;padding:12px 0;font-family:Arial,sans-serif\"\u003e\n\u003cdiv style=\"display:grid;grid-template-columns:1fr 1fr 1fr;gap:0;margin-bottom:24px\"\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e◆\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eBright finish HSS-Co5 (Cobalt) for extreme tool life.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e●\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eUse to enlarge the top of an existing hole to create a cylindrical-shaped opening with a flat bottom that acts as a seat for the head of a screw or wood plug.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e▲\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eIdeal for use with standard cap screws or socket head screws.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size:14px;color:#444;line-height:1.7;margin:0\"\u003e6 Pce 3-10mm 180 Degree Counterbore Drill Set. Bright finish HSS-Co5 (Cobalt) for extreme tool life Designed for demanding countersink bit applications. A practical choice for hss drill bits requirements in trade and industrial environments.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Bordo","offers":[{"title":"Default Title","offer_id":49296753230101,"sku":"A0145317","price":1063.57,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0740\/5191\/1957\/files\/bordo-3871-set-3-10mm-6pieces-8154241.jpg?v=1781510953"},{"product_id":"bordo-180-degree-counterbore-3870","title":"Bordo 180 Degree Counterbore (3870)","description":"\u003cdiv style=\"max-width:680px;width:100%;padding:12px 0;font-family:Arial,sans-serif\"\u003e\n\u003cdiv style=\"display:grid;grid-template-columns:1fr 1fr 1fr;gap:0;margin-bottom:24px\"\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e◆\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eBright finish HSS-Co5 (Cobalt) for extreme tool life.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e●\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eUse to enlarge the top of an existing hole to create a cylindrical-shaped opening with a flat bottom that acts as a seat for the head of a screw or wood plug.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e▲\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eIdeal for use with standard cap screws or socket head screws.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size:14px;color:#444;line-height:1.7;margin:0\"\u003e180 Degree Counterbore for M3 Screws. Bright finish HSS-Co5 (Cobalt) for extreme tool life. Designed for demanding countersink bit applications.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Bordo","offers":[{"title":"6 x 3.2mm","offer_id":49324843204885,"sku":"A0205516","price":119.97,"currency_code":"AUD","in_stock":true},{"title":"6.5 x 3.7mm","offer_id":49324843237653,"sku":"A0205517","price":119.97,"currency_code":"AUD","in_stock":true},{"title":"8 x 4.3mm","offer_id":49324843270421,"sku":"A0205518","price":121.25,"currency_code":"AUD","in_stock":true},{"title":"10 x 5.3mm","offer_id":49324843303189,"sku":"A0205519","price":138.4,"currency_code":"AUD","in_stock":true},{"title":"11 x 6.4mm","offer_id":49324843335957,"sku":"A0205520","price":156.16,"currency_code":"AUD","in_stock":true},{"title":"15 x 8.4mm","offer_id":49324843368725,"sku":"A0205521","price":214.21,"currency_code":"AUD","in_stock":true},{"title":"18 x 10.5mm","offer_id":49324843401493,"sku":"A0205522","price":280.07,"currency_code":"AUD","in_stock":true},{"title":"20 x 13mm","offer_id":49324843434261,"sku":"A0205523","price":381.59,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0740\/5191\/1957\/files\/bordo-180-degree-counterbore-3870-3231728.jpg?v=1779090022"},{"product_id":"bordo-180-degree-counterbore-drill-3871","title":"Bordo 180 Degree Counterbore Drill (3871)","description":"\u003cdiv style=\"max-width:680px;width:100%;padding:12px 0;font-family:Arial,sans-serif\"\u003e\n\u003cdiv style=\"display:grid;grid-template-columns:1fr 1fr 1fr;gap:0;margin-bottom:24px\"\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e◆\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eBright finish HSS-Co5 (Cobalt) for extreme tool life.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;border-right:1px solid #e0e0e0;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e●\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eUse to enlarge the top of an existing hole to create a cylindrical-shaped opening with a flat bottom that acts as a seat for the head of a screw or wood plug.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding:12px 16px;\"\u003e\n\u003cdiv style=\"font-size:18px;margin-bottom:6px\"\u003e▲\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;font-weight:600;color:#333;line-height:1.4\"\u003eIdeal for use with standard cap screws or socket head screws.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size:14px;color:#444;line-height:1.7;margin:0\"\u003e180 Degree Counterbore Drill for M3 Screws. Bright finish HSS-Co5 (Cobalt) for extreme tool life. Designed for demanding countersink bit applications.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Bordo","offers":[{"title":"6 x 3.4mm","offer_id":49324853428501,"sku":"A0205524","price":149.94,"currency_code":"AUD","in_stock":true},{"title":"8 x 4.5mm","offer_id":49324853461269,"sku":"A0205525","price":151.58,"currency_code":"AUD","in_stock":true},{"title":"10 x 5.5mm","offer_id":49324853494037,"sku":"A0205526","price":173.02,"currency_code":"AUD","in_stock":true},{"title":"11 x 6.6mm","offer_id":49324853526805,"sku":"A0205527","price":195.26,"currency_code":"AUD","in_stock":true},{"title":"15 x 9mm","offer_id":49324853559573,"sku":"A0205528","price":268.87,"currency_code":"AUD","in_stock":true},{"title":"18 x 11mm","offer_id":49324853592341,"sku":"A0205529","price":393.78,"currency_code":"AUD","in_stock":true},{"title":"20 x 14mm","offer_id":49324853625109,"sku":"A0205530","price":515.36,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0740\/5191\/1957\/files\/bordo-180-degree-counterbore-drill-3871-5888966.jpg?v=1779090021"}],"url":"https:\/\/aimsindustrial.com.au\/en-nz\/collections\/counterbores.oembed","provider":"AIMS Industrial Supplies","version":"1.0","type":"link"}