Length for 3-10mm covers is 15mm.
eBay
38# M4/M5/M6/M8 Z-type Hand Nut Plastic Handle Screw Cap Straight Type Rubber Head Nut Wood Bolt Cap
Aliexpress UK
Perfect for maintaining any grease / coating you may use on the ball hitch. Fits all standard flange / bolt on tow balls. Designed to cover full ball hitch (front part of mounting bracket ) and improve looks.
eBay
5-50pcs rubber end caps, vinyl end caps with black and red screws, bolts, screws, rubber thread protectors, safety covers
Aliexpress UK
About the product:The rubber end caps sleeve on the screw and bolt, which can prevent rusting, isolate dust, protect the thread, and protect the surface from scratches. The vinyl covers are widely used in homes and industries. Suitable for yard fence railing, metal tip, round tubing, pipe, hook, rod end, etc.Good Choice for you:Rubber material, soft, wear-resistant, with good elasticity. Vinyl end caps are with good insulation and can be used in electrical applications.Specification:Color: Black;Rubber material;Inner dia: 12mm/0.47inchIn the package of: 50 Pack x Rubber end capsEasy to install:Easy to install and use. The round end caps sleeve on various screws and bolts for protection. Waterproof, nonslip, suitable for outdoor use.Tips: Please confirm the correct size before ordering.
eBay
10/25/50pc rubber end cap, screw end cap, plastic tube, hub thread protector, push in cap, rubber cap, rubber threaded cap
Aliexpress UK
About the product:The rubber end caps sleeve on the screw and bolt, which can prevent rusting, isolate dust, protect the thread, and protect the surface from scratches. The vinyl covers are widely used in homes and industries. Suitable for yard fence railing, metal tip, round tubing, pipe, hook, rod end, etc.Good Choice for you:Rubber material, soft, wear-resistant, with good elasticity. Vinyl end caps are with good insulation and can be used in electrical applications.Specification:Color: White;Rubber material;Inner dia: 5mm/0.2-inchIn the package of: 100 Pack x Rubber end capsEasy to install:Easy to install and use. The round end caps sleeve on various screws and bolts for protection. Waterproof, nonslip, suitable for outdoor use.Tips: Please confirm the correct size before ordering.
eBay
10-50pc PVCrubber end cap, screw end cap, plastic tube, hub thread protector, push in cap, rubber cap, rubber threaded cap
Aliexpress UK
Designed to grip onto a 6mm thread. Will work on bars/tubes from about 5.5mm to 6.5mm. Ideal for covering exposed threads on the ends of bolts or covering the open ends of tube etc.
eBay
White/Black Silicone Rubber Round Caps Protection Gasket Dust Seal End Cover Caps For Pipe Bolt Furniture 3mm-78.5mm
Aliexpress UK
Description:[PVC Material] These rubber end caps are made of PVC material, which is flexible and insulating, and also has the characteristics of anti-corrosion and wear resistance, with fine workmanship.[Practical Tools] These rubber end caps not only prevent dust and rust, extend the service life of screws, but also serve as a good helper for furniture because these soft rubber end caps can prevent scratches on kitchen or wooden floors.[Wide Application] Great for covering screws or other threaded parts, round tubes, furniture feet, pipes, hooks, iron rods, cables, cylinders, etc., with a wide range of applications, even everywhere in the home.[Note/Size Selection] If you want to use it firmly, please buy the size you need, it can be smaller, but not larger, it may fall off if it is larger.
eBay
50Pcs Hex Nut Cover, White Black M4 M5 M6 M8 M10 M12 Bolt Dome Caps Covers ,Plastic Dome Bolt Nut Protection Caps Cover for Bolt
Aliexpress UK
Description:[PVC Material] These rubber end caps are made of PVC material, which is flexible and insulating, and also has the characteristics of anti-corrosion and wear resistance, with fine workmanship.[Practical Tools] These rubber end caps not only prevent dust and rust, extend the service life of screws, but also serve as a good helper for furniture because these soft rubber end caps can prevent scratches on kitchen or wooden floors.[Wide Application] Great for covering screws or other threaded parts, round tubes, furniture feet, pipes, hooks, iron rods, cables, cylinders, etc., with a wide range of applications, even everywhere in the home.[Note/Size Selection] If you want to use it firmly, please buy the size you need, it can be smaller, but not larger, it may fall off if it is larger.
eBay
50pcs Rubber Round Tube End Push-in Cap Cover M6 M8 M10 M12 Pipe Plug Screw Thread Protector Bolt Safety Chair Feet Table Tip
Aliexpress UK
Description:[PVC Material] These rubber end caps are made of PVC material, which is flexible and insulating, and also has the characteristics of anti-corrosion and wear resistance, with fine workmanship.[Practical Tools] These rubber end caps not only prevent dust and rust, extend the service life of screws, but also serve as a good helper for furniture because these soft rubber end caps can prevent scratches on kitchen or wooden floors.[Wide Application] Great for covering screws or other threaded parts, round tubes, furniture feet, pipes, hooks, iron rods, cables, cylinders, etc., with a wide range of applications, even everywhere in the home.[Note/Size Selection] If you want to use it firmly, please buy the size you need, it can be smaller, but not larger, it may fall off if it is larger.
eBay
50pcs Rubber Round Tube End Push-in Cap Cover M6 M8 M10 M12 Pipe Plug Screw Thread Protector Bolt Safety Chair Feet Table Tip
Aliexpress UK