Screws/bolts with patches

A patch is a dot placed on the thread or a layer that completely surrounds the thread of a screw. The dot/layer is usually polymer or wax based and is added to achieve a specific function, such as prevailing torque, sealing or additional lubrication. Bulten can offer a wide range of patch solutions to meet any customer requirement.
Different patches to secure screws/bolts from loosening – prevailing torque
There are several methods that can be used to secure a screw or a bolt against self-loosening. Below we describe some variations available by patching threads. You can also read about self-locking designs here.
Mechanical friction locking patch
This dry thread-locking solution typically involves applying plastic to 180° of the external thread, and is customizable for locking strength, temperature resistance, and chemical exposure.
The pre-coated surface increases pressure on the mating threads, forcing the opposite side of the screw into contact and creating friction that prevents loosening.
Key properties
- Instant, controllable strength
- Reusable up to five times
- Allows component adjustments
- Complies with DIN 267-28 and automotive standards
Types
Mechanical friction locking
Dri-Loc® Plastic, Tufloc, etc
Micro-encapsulated thread locking patch
Designed to solve sticky and costly problems, this solution uses micro-bubbles of locking liquid held in place by a bonding agent pre-applied to the threads.
When fasteners are assembled, the bubbles break, releasing the liquid, which begins hardening immediately and fully cures within 12 hours at room temperature.
Key properties
- Equivalent performance to liquid thread lockers
- Effective sealing and vibration resistance
- Operating temperature: –55°C to 150°C
- Single use, with a 3-year shelf life
Types
Microencapsulated thread locking
Precote® 85 (80), Loctite DRI® 2045 (40)
Patches to prevent leakage in screw threads
Leak prevention patches can be applied to any type of bolt where leakage through the thread needs to be prevented. The patch is typically applied around the thread (360˚), a distance up the shank.
Types
Thread sealing
Dri-Seal®
Precote®
Patches to provide lubrication during difficult assembly
Lubricating patches are primarily designed to reduce assembly torque on thread-forming screws such as TAPTITE®. Lubricating patches are typically applied to the entire tip of the bolt (360˚ around.) These patches prevent cutting and are particularly suitable for manual assembly to prevent operator injury.
Types
Lubrication
TOP300