Where do you look for DIY parts?

Given the upcoming contest(thanks again the and Justin) I thought it might be a good idea to start a thread just for listing DIY parts that aren’t flashlight parts but may come in handy in a scratch made contest. Switches, lenses, reflectors or optics, drivers, and LEDs are allowed but nothing else from a host may be used so how do you make these accessible and where do you find the bits that make it possible. I find salvage yards very handy for locating odd bits, much more so than most any store and a lot more reasonably priced. Sink drains and tub drains are often made of solid brass and have much finer threading than tapered pipe thread or compression fittings though 5/8” comp is perfect for 18650 tubes. I’ll be adding some pics of a few of the parts I use and how I alter them from time to time.

Please limit posts to helpful additions so that there’s less to wade through.

K&S Precision Metals probably my most oft used resource for thin wall brass tubing. Unfortunately doesn’t come in an ID to easily fit 18650’s but perfect for AA or AAA and with extensive reaming the thicker walled 3/4” X …029” can just fit the thinnest sizes of 18650’s (not protected) and in stock form fits 16650’s nicely. Lots of hardware and hobby stores carry their parts in a display stand.

Check your local ‘machine / job shop’ listings. They often have odd bits of stock / tubing for the asking. Also check w/ local commercial electrical contractors, rigid Al conduit has a heavier wall OD to ID. I know that 1” conduit will fit 18650 cells.

You never know what you will find at Surplus Shed .
That place is an inventor/tinkerer’s dream.

Believe it or not I by a fair bit from Fasttech. Switches, some lights, drivers, batteries, springs, etc.

Onlinemetalsupply and ebay

Lowe's, Home Depot for copper, brass and small parts, Harbor Freight for cheap tools. Local metal shops for aluminum, copper, brass rod stock. Onlinemetalsupply, eBay, surprisingly, for just about anything at times. Tons of websites for all different items, just do Google searches.

I know it's harder for other countries. There's so much more available in the US, it seems sometimes.

Kaidomain for reflectors, and some leds. Fasttech for other components, Richard, RMM, whenever he has what I needed.

Mouser and Digikey for leds and other electrnic cmponents sometimes.

@Old-Lumens Thanks for fleshing out the list.