TC Bros. Blind Threaded (Top Hat-Style) Mounting Bungs

A diagram showing the dimensions of TC Bros.&

Four Tophat Style Blind Threaded 5/16-18 Steel Bungs by TC Bros on a white background.

Four Tophat Style Blind Threaded 3/8-16 Steel Bungs by TC Bros on a white background, ensuring a leak free mount.

$21.95

Size

5/16"-18 × 1/2"

3/8"-16 × 1/2"

In stock
Inventory on the way

[{"id":49554619662529,"title":"5\/16\"-18 × 1\/2\"","option1":"5\/16\"-18 × 1\/2\"","option2":null,"option3":null,"sku":"104-0056","requires_shipping":true,"taxable":true,"featured_image":{"id":32138893820097,"product_id":10816584253633,"position":2,"created_at":"2022-04-04T23:02:12-04:00","updated_at":"2025-09-22T12:51:55-04:00","alt":"A diagram showing the dimensions of TC Bros.' Tophat Style Blind Threaded 5\/16-18 Steel Bungs for mounts or bungs.","width":800,"height":800,"src":"\/\/tcbros.com\/cdn\/shop\/products\/104-0056.1.jpg?v=1758559915","variant_ids":[49554619662529]},"available":true,"name":"TC Bros. Blind Threaded (Top Hat-Style) Mounting Bungs - 5\/16\"-18 × 1\/2\"","public_title":"5\/16\"-18 × 1\/2\"","options":["5\/16\"-18 × 1\/2\""],"price":2195,"weight":0,"compare_at_price":null,"inventory_management":"shopify","barcode":"7C1-3","featured_media":{"alt":"A diagram showing the dimensions of TC Bros.' Tophat Style Blind Threaded 5\/16-18 Steel Bungs for mounts or bungs.","id":24435767705793,"position":2,"preview_image":{"aspect_ratio":1.0,"height":800,"width":800,"src":"\/\/tcbros.com\/cdn\/shop\/products\/104-0056.1.jpg?v=1758559915"}},"requires_selling_plan":false,"selling_plan_allocations":[],"quantity_rule":{"min":1,"max":null,"increment":1}},{"id":49554626773185,"title":"3\/8\"-16 × 1\/2\"","option1":"3\/8\"-16 × 1\/2\"","option2":null,"option3":null,"sku":"104-0057","requires_shipping":true,"taxable":true,"featured_image":{"id":32138894508225,"product_id":10816584253633,"position":4,"created_at":"2022-04-04T23:02:20-04:00","updated_at":"2025-09-22T12:51:55-04:00","alt":"A diagram showing the dimensions of TC Bros' Tophat Style Blind Threaded 3\/8-16 Steel Bungs hole.","width":800,"height":800,"src":"\/\/tcbros.com\/cdn\/shop\/products\/104-0057.1.jpg?v=1758559915","variant_ids":[49554626773185]},"available":true,"name":"TC Bros. Blind Threaded (Top Hat-Style) Mounting Bungs - 3\/8\"-16 × 1\/2\"","public_title":"3\/8\"-16 × 1\/2\"","options":["3\/8\"-16 × 1\/2\""],"price":2195,"weight":0,"compare_at_price":null,"inventory_management":"shopify","barcode":"8B1-3","featured_media":{"alt":"A diagram showing the dimensions of TC Bros' Tophat Style Blind Threaded 3\/8-16 Steel Bungs hole.","id":24435768426689,"position":4,"preview_image":{"aspect_ratio":1.0,"height":800,"width":800,"src":"\/\/tcbros.com\/cdn\/shop\/products\/104-0057.1.jpg?v=1758559915"}},"requires_selling_plan":false,"selling_plan_allocations":[],"quantity_rule":{"min":1,"max":null,"increment":1}}]

Hassle-free 90 Day Returns

Free USA Shipping for Orders Over $99*

Free Tech Support M-F 8:30am-4:30pm EST

Fast Shipping—No Backorders, No Drop Shipping, No BS

TC Bros. Blind Threaded (Top Hat-Style) Mounting Bungs

Save time and create super-strong mount points for just about anything on your bike using these blind threaded bungs for your project.

Bungs are American-made 1018 mild steel that's a breeze to weld
CNC-machined for symmetry and accuracy
Blind design particularly well suited to mounting items containing fluid like oil bags or fuel tanks where a plain bung could leak
Corresponding fastener not included
Sold as a set of 4

Save fabrication time with these rugged, reliable bungs from TC Bros. They're especially helpful when mounting items that contain a liquid. The blind design prevents fluids from infiltrating the threads as a plain bung might permit. Make sure your mounting point is just a mounting point and not an accidental drain port with top hat bungs from TC Bros.

We offer these because we need them when we build motorcycles, so we're pretty sure you'll find them handy, too. Pick up a variety today and see what uses you can find for these on your project.