{"id":71,"date":"2026-09-04T16:30:00","date_gmt":"2026-09-04T14:30:00","guid":{"rendered":"https:\/\/www.matai.cz\/blog\/?p=71"},"modified":"2026-08-31T17:19:59","modified_gmt":"2026-08-31T15:19:59","slug":"din-912-valcova-hlava-imbus-norma","status":"publish","type":"post","link":"https:\/\/www.matai.cz\/blog\/din-912-valcova-hlava-imbus-norma\/","title":{"rendered":"DIN 912 \u0161rouby s v\u00e1lcovou hlavou a vnit\u0159n\u00edm \u0161estihranem: v\u00fdklad"},"content":{"rendered":"

\u0160roub podle normy DIN 912<\/strong> pat\u0159\u00ed k nejpou\u017e\u00edvan\u011bj\u0161\u00edm spojovac\u00edm prvk\u016fm ve stroj\u00edrenstv\u00ed a p\u0159esn\u00e9 mont\u00e1\u017ei. Lidov\u011b se mu \u0159\u00edk\u00e1 \u201eimbus\u201c nebo \u201einbusov\u00fd \u0161roub\u201c, proto\u017ee se dotahuje kl\u00ed\u010dem na vnit\u0159n\u00ed \u0161estihran. Tento \u010dl\u00e1nek vysv\u011btluje, co norma DIN 912 popisuje, jak\u00e9 m\u00e1 dan\u00fd \u0161roub rozm\u011bry, jak\u00e9 jsou dostupn\u00e9 t\u0159\u00eddy pevnosti a materi\u00e1ly a kdy ho v praxi nasadit.<\/p>\n

Co norma DIN 912 popisuje<\/h2>\n

DIN 912 definuje \u0161roub s v\u00e1lcovou hlavou a vnit\u0159n\u00edm \u0161estihranem<\/strong> (anglicky hexagon socket head cap screw). Charakteristick\u00fdm znakem je n\u00edzk\u00e1 v\u00e1lcov\u00e1 hlava s otvorem pro kl\u00ed\u010d na vnit\u0159n\u00ed \u0161estihran a metrick\u00fd z\u00e1vit. Mezin\u00e1rodn\u00edm prot\u011bj\u0161kem je norma ISO 4762<\/strong>; v praxi se ob\u011b ozna\u010den\u00ed pou\u017e\u00edvaj\u00ed jako rovnocenn\u00e1 a d\u00edly b\u00fdvaj\u00ed vz\u00e1jemn\u011b zam\u011bniteln\u00e9. Rozd\u00edly se historicky t\u00fdkaly jen n\u011bkter\u00fdch mal\u00fdch rozm\u011br\u016f, pro b\u011b\u017en\u00e9 velikosti od M3 v\u00fd\u0161e jsou rozm\u011bry shodn\u00e9.<\/p>\n

Pokud pot\u0159ebujete detailn\u00ed rozbor p\u0159echodu mezi n\u011bmeckou a mezin\u00e1rodn\u00ed normou, v\u011bnujeme se mu v samostatn\u00e9m textu ISO 4762 a jej\u00ed vztah k DIN 912<\/a>.<\/p>\n

Geometrie \u0161roubu DIN 912<\/h2>\n

Hlava je relativn\u011b mal\u00e1 a vejde se do zahlouben\u00ed (v\u00e1lcov\u00e9ho i ku\u017eelov\u00e9ho), tak\u017ee \u0161roub m\u016f\u017ee b\u00fdt v mont\u00e1\u017ei zcela zapu\u0161t\u011bn\u00fd. To je hlavn\u00ed v\u00fdhoda oproti \u0161estihrann\u00e9 hlav\u011b, kter\u00e1 vy\u017eaduje prostor pro kl\u00ed\u010d zven\u010d\u00ed. Pro orientaci plat\u00ed p\u0159ibli\u017en\u00e1 pravidla: pr\u016fm\u011br hlavy dk<\/em> je zhruba 1,5n\u00e1sobek pr\u016fm\u011bru z\u00e1vitu, v\u00fd\u0161ka hlavy k<\/em> je zhruba rovna jmenovit\u00e9mu pr\u016fm\u011bru z\u00e1vitu.<\/p>\n

Rozm\u011brov\u00e1 tabulka (b\u011b\u017en\u00e9 velikosti)<\/h2>\n

N\u00e1sleduj\u00edc\u00ed hodnoty odpov\u00eddaj\u00ed DIN 912 \/ ISO 4762 a vych\u00e1zej\u00ed z technick\u00fdch list\u016f v\u00fdrobc\u016f spojovac\u00edho materi\u00e1lu. Uvedeny jsou jmenovit\u00e9 (maxim\u00e1ln\u00ed) rozm\u011bry; pro p\u0159esn\u00e9 tolerance v\u017edy konzultujte aktu\u00e1ln\u00ed zn\u011bn\u00ed normy nebo katalogov\u00fd list.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
Z\u00e1vit (d)<\/th>\nStoup\u00e1n\u00ed (P)<\/th>\nPr\u016fm\u011br hlavy dk (max)<\/th>\nV\u00fd\u0161ka hlavy k<\/th>\nKl\u00ed\u010d na vnit\u0159n\u00ed \u0161estihran (s)<\/th>\n<\/tr>\n<\/thead>\n
M3<\/td>\n0,5 mm<\/td>\n5,5 mm<\/td>\n3 mm<\/td>\n2,5 mm<\/td>\n<\/tr>\n
M4<\/td>\n0,7 mm<\/td>\n7 mm<\/td>\n4 mm<\/td>\n3 mm<\/td>\n<\/tr>\n
M5<\/td>\n0,8 mm<\/td>\n8,5 mm<\/td>\n5 mm<\/td>\n4 mm<\/td>\n<\/tr>\n
M6<\/td>\n1,0 mm<\/td>\n10 mm<\/td>\n6 mm<\/td>\n5 mm<\/td>\n<\/tr>\n
M8<\/td>\n1,25 mm<\/td>\n13 mm<\/td>\n8 mm<\/td>\n6 mm<\/td>\n<\/tr>\n
M10<\/td>\n1,5 mm<\/td>\n16 mm<\/td>\n10 mm<\/td>\n8 mm<\/td>\n<\/tr>\n
M12<\/td>\n1,75 mm<\/td>\n18 mm<\/td>\n12 mm<\/td>\n10 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Kl\u00ed\u010d na vnit\u0159n\u00ed \u0161estihran (rozm\u011br s<\/em>) je d\u016fle\u017eit\u00fd zejm\u00e9na p\u0159i objedn\u00e1vce n\u00e1\u0159ad\u00ed: u b\u011b\u017en\u00fdch velikost\u00ed plat\u00ed M4 \u2192 kl\u00ed\u010d 3 mm, M6 \u2192 kl\u00ed\u010d 5 mm, M8 \u2192 kl\u00ed\u010d 6 mm, M10 \u2192 kl\u00ed\u010d 8 mm, M12 \u2192 kl\u00ed\u010d 10 mm.<\/p>\n

Materi\u00e1ly a t\u0159\u00eddy pevnosti<\/h2>\n

\u0160rouby DIN 912 se vyr\u00e1b\u011bj\u00ed v uhl\u00edkov\u00e9 oceli i v nerezu. U ocelov\u00fdch proveden\u00ed jsou typick\u00e9 t\u0159\u00eddy pevnosti 8.8, 10.9 a 12.9<\/strong>; vy\u0161\u0161\u00ed t\u0159\u00eddy se pou\u017e\u00edvaj\u00ed tam, kde je pot\u0159eba p\u0159en\u00e1\u0161et velk\u00e9 zat\u00ed\u017een\u00ed v mal\u00e9m z\u00e1stavbov\u00e9m prostoru (formy, p\u0159\u00edpravky, hydraulika). K rozd\u00edlu mezi nejvy\u0161\u0161\u00edmi t\u0159\u00eddami se vrac\u00edme v \u010dl\u00e1nku o t\u0159\u00edd\u00e1ch pevnosti \u0161roub\u016f<\/a>.<\/p>\n

V korozn\u011b n\u00e1ro\u010dn\u00fdch aplikac\u00edch s\u00e1hn\u011bte po nerezu. Ozna\u010den\u00ed A2-70<\/strong> (b\u011b\u017en\u00e1 nerez, nap\u0159. 1.4301) a A4-80<\/strong> (kyselinovzdorn\u00e1 nerez s molybdenem) ud\u00e1v\u00e1 jak materi\u00e1lovou skupinu, tak t\u0159\u00eddu pevnosti: \u010d\u00edslo za poml\u010dkou znamen\u00e1 1\/10 minim\u00e1ln\u00ed meze pevnosti v tahu v N\/mm\u00b2, tedy A2-70 odpov\u00edd\u00e1 \u2265700 N\/mm\u00b2. Rozd\u00edl mezi ob\u011bma skupinami a kdy kter\u00e1 sta\u010d\u00ed rozeb\u00edr\u00e1me v textu nerez A2 vs. A4<\/a>.<\/p>\n

Pozor: u nerezov\u00fdch imbusov\u00fdch \u0161roub\u016f hroz\u00ed p\u0159i dotahov\u00e1n\u00ed zad\u00edr\u00e1n\u00ed z\u00e1vitu<\/em> (galling). U v\u011bt\u0161\u00edch pr\u016fm\u011br\u016f a vy\u0161\u0161\u00edch moment\u016f doporu\u010dujeme mont\u00e1\u017en\u00ed pastu proti zad\u00edr\u00e1n\u00ed.<\/p>\n

Kdy DIN 912 nasadit<\/h2>\n