{"id":113,"date":"2026-09-18T10:00:00","date_gmt":"2026-09-18T06:30:00","guid":{"rendered":"https:\/\/sanatiblog.ir\/blog\/drill-bits-and-cutting-discs\/"},"modified":"2026-09-18T10:00:00","modified_gmt":"2026-09-18T06:30:00","slug":"drill-bits-and-cutting-discs","status":"publish","type":"post","link":"https:\/\/sanatiblog.ir\/fa\/blog\/drill-bits-and-cutting-discs\/","title":{"rendered":"\u0645\u062a\u0647 \u0648 \u0635\u0641\u062d\u0647\u200c\u0633\u0646\u06af: \u0628\u0631\u0627\u06cc \u0647\u0631 \u062c\u0646\u0633\u060c \u06a9\u062f\u0627\u0645\u061f"},"content":{"rendered":"<p>A wrong bit is slow at best, and at worst it burns, snaps or ruins the hole. A wrong disc can break apart at full speed. Here is the short version.<\/p>\n<h2>Drill bits<\/h2>\n<ul>\n<li><strong>Steel:<\/strong> HSS (high speed steel) bits. Ground ones last longer than the cheap rolled ones.<\/li>\n<li><strong>Stainless steel:<\/strong> HSS-Co (with cobalt, often 5%). Drill slowly, press firmly, and use cutting oil.<\/li>\n<li><strong>Brick and light concrete:<\/strong> masonry bits with a carbide tip, in a hammer drill.<\/li>\n<li><strong>Hard concrete:<\/strong> SDS-plus bits in a rotary hammer. They do not fit an ordinary chuck.<\/li>\n<li><strong>Wood:<\/strong> wood bits with a centre point, so the bit does not wander.<\/li>\n<\/ul>\n<h2>Cutting and grinding discs<\/h2>\n<ul>\n<li><strong>Size:<\/strong> the disc must match your grinder: 115, 125, 180 or 230 mm, with the right centre hole (usually 22.23 mm).<\/li>\n<li><strong>Speed:<\/strong> the maximum speed printed on the disc must be higher than your grinder&#8217;s speed. Never the other way round.<\/li>\n<li><strong>Thickness:<\/strong> thin discs (1 mm) cut steel fast and clean; thicker ones are for rough work. Never grind with the side of a cutting disc.<\/li>\n<li><strong>Stainless steel:<\/strong> use discs marked INOX, so you do not leave rust spots on the steel.<\/li>\n<li><strong>Date:<\/strong> resin discs have an expiry date printed on the metal ring. Old discs can break.<\/li>\n<\/ul>\n<p>Keep the guard on the grinder. It is there for the day a disc breaks.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u06a9\u062f\u0627\u0645 \u0645\u062a\u0647 \u0628\u0631\u0627\u06cc \u0622\u0647\u0646\u060c \u0627\u0633\u062a\u06cc\u0644 \u0648 \u0628\u062a\u0646\u060c \u0648 \u0633\u0647 \u0642\u0627\u0646\u0648\u0646 \u0627\u06cc\u0645\u0646\u06cc \u0628\u0631\u0627\u06cc \u0635\u0641\u062d\u0647\u200c\u06cc \u0641\u0631\u0632.<\/p>\n","protected":false},"author":0,"featured_media":128,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-113","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts\/113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/comments?post=113"}],"version-history":[{"count":0,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts\/113\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/media\/128"}],"wp:attachment":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/media?parent=113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/categories?post=113"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/tags?post=113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}