The force required to initiate the first relative movement between the bolt and the mating part.
In heavy-duty industries like automotive, aerospace, and petrochemicals, traditional nuts and bolts often face the risk of self-loosening due to vibration or thermal expansion. specifies the functional characteristics of steel screws, bolts, and studs that are pre-coated with micro-encapsulated adhesives to mitigate these risks. 1. Scope and Technical Specifications The standard applies to a wide range of metric fasteners: Thread Type: ISO metric threads (coarse and fine pitch). Diameter Range: M3 to M39.
Certain MK coatings are rated for service temperatures up to +150∘Cpositive 150 raised to the composed with power C . din 26727 pdf hot
The torque needed to continue unscrewing the bolt after the initial bond has been broken.
The "hot" aspect of this keyword likely refers to the standard’s rigorous testing for . DIN 267-27 is designed for extreme thermal reliability: Standard Range: Typically tested for use from -50∘Cnegative 50 raised to the composed with power C +100∘Cpositive 100 raised to the composed with power C The force required to initiate the first relative
The micro-encapsulated adhesive remains dormant until assembly. When the bolt is screwed into a nut or tapped hole, the capsules burst, releasing the adhesive and initiating the curing process. 2. Performance at High Temperatures ("Hot" Applications)
The standard requires system tests at room temperature and at these elevated limits to ensure the adhesive bond does not degrade or liquefy under heat. For these tests, specialized ovens meeting DIN 50011-12 accuracy classes are used. 3. Critical Testing and Verification Certain MK coatings are rated for service temperatures
Steel and stainless steel fasteners according to ISO 898-1 and ISO 3506-1 .