Off the shelf SS drinking straws are often unsatisfactory for 2 primary reasons:
- Too thin (not enough fluid flow)
- Too tall (too easy to knock the cup over, poke an eye out, or accidentally pick a booger)
But, a straw should be easy to DIY. It's a tube. No welding. No joinery. It's an empty tube...full of opportunity.
You get to decide fluid flow, quality, and height. This Instructable is *not* about cutting a piece of metal. It's about designing and making a straw that's custom and right for you.
One 36" piece of high-grade stainless steel will make 3 or 4 straws.
Make. Give. Enjoy.
Step 1: Choose the Right Internal Diameter (ID)
This is the first and most important step. Most pre-made SS drinking straws on the market have a super narrow internal diameter.
A pink Braums straw has the perfect ID in my opinion. It works very well for both water and malts. So, I set out to find a stick of SS tubing with a similar ID.
Step 2: Choose the Right Wall Thickness
Too thin of a wall can be sharp & therefore painful.
Too thick of a wall can make the straw heavy and/or not fit into the lid hole.
I opted for a thick wall. I like the extra weight. And as far as the lid hole goes - I do have to slightly enlarge the lid hole opening on some lids...but this straw only stays in 1 or 2 cups anyway. So, to me, this is a small trade-off for the benefits of a large ID and a thick wall.
Step 3: Choose Grade of Stainless Steel
Some premade straws don't mention their grade of stainless steel. That's disconcerting. Of the ones that do, most seem to be grade 304.
I went straight up to 316L to play it safe and feel good about it. Better corrosion resistance, less chance of allergies, etc.
Here's the site pictured in the thumbnail. It has clear information about various grades of stainless steel: https://continentalsteel.com/stainless-steel/grade...
Step 4: Buy It
If you live in a large city, you probably have a stainless steel supplier that could sell you the exact amount of stainless steel you need.
Otherwise, there are several steel suppliers online that ship to residential addresses. When considering shipping, I found Amazon to be the cheapest for just a few feet of tubing. Whichever way you go, here are the specs I decided on:
- Stainless Steel grade 316L
- ID: 0.277"
- Wall: 0.049"
Here's the item I used: https://amzn.to/2EutMaz
Step 5: Cut to Length
Most pre-made straws are annoyingly tall. When making your own straw, you have the luxury of defining your own straw height. Put it in your cup and mark where you'd like to cut it.
I chose for it to rise above the lid about 1".
There are many ways to cut metal (grinder, hacksaw, metal bandsaw, cutoff tool, dremel, tubing cutter, etc). Choose the method you feel good about, then make it happen.
Step 6: De-Burr (but Don't Sharpen)
After cutting the tubing, you'll have some sharp edges. Sand/grind them down using some sort of fine grinding/sanding tool. Use a small file to remove the inner burr.
Step 7: Wipe Off Markings With Alcohol
The stainless steel tubing will more than likely be marked with either:
- Blue text printed with dots. If so, that's a good thing. It can be wiped off with alcohol.
- Text stamped/engraved/punched into the surface. This will not wipe off with alcohol, so either embrace it or find tubing that has the blue text instead.
Step 8: Enlarge Lid Hole (if Necessary)
If your straw doesn't fit into the lid, make the hole bigger using either a file or a Dremel. Keep in mind that the plastic used for these lids is usually very hard, so avoid a tool with too much bite. Skip the aggressive cutting tools. File, sand, or grind instead.
Step 9: Wash and Enjoy!
I used pipe cleaners to clean the inside of my straw. I don't know the proper way to clean stainless steel for this type of thing, so I first cleaned with vinegar, then with dish soap and hot water. If you know a proper way to clean SS drinking straws, leave a comment.
Step 10: Materials and Tools
You only need a stick of Stainless Steel Tubing. If you like a pink Braums straw, this one will probably work for you. If you prefer thinner/thicker, use these dimensions as a starting point for comparison.
For price/performance, I'd recommend this WEN rotary tool kit. I own two of them. It includes everything you need for this project: the rotary tool itself, metal-cutting discs, grinding bits, sanding parts, and a flex shaft for a super cool bonus!