This isn't an answer to your question but it works for me. Take a few tubes to your local bicycle store and take a look at their selection of wheel spokes. Find one that fits and buy it along with the nut that they come with. Cut it to length, about an inch or so longer that your usual tube length. Clamp it in your vise with the nut end out. Slide your tube on, tighten nut , presto. No more spinning. I usually tie on air brake tubing which is 1/8" OD and sometimes use a small rubber bumper.
You can make your own replacement mandrel for the HMH tube tool with single strand stainless steel leader wire. #10 wire (.024) will fit inside the 3/32 inch O.D. tubing. It also fits inside the HMH Micro tubing. #9 wire (.022) is stiff enough, too.
Directions: Cut a six-inch length from the leader coil. With pliers make a right angle bend two inches from one end. Cut off the wire on the short leg about 1/8 inch from the bend, forming a little hook at the tip of the shaft. Slide the shaft into the tube tool as usual. When you pull back on the shaft and screw down the clamp, the hook will hold the tube securely in place. The wire eventually gets deformed by the downward pressure of the clamp (as does the HMH fine-diameter mandrel). If you care about that, cut off another length of wire from the coil and make another one in about a minute. I’ve never had a leader-wire mandrel break, but I do lose them now and then. One nine-dollar, 25-foot coil of wire will make enough replacement mandrels to last you a lifetime.
I’ve tied on an HMH tube tool exclusively for more than a decade. Somewhere along the line I lost the fine mandrel, too. I started using single strand leader wire while waiting for a replacement to be shipped. The new mandrel is still in the bag, unused.
Hope this helped.
That is most gratifying to hear. We (Bob Kenly, Craig Wester, Kathy Johnson, the superbly talented layout artist, and all 35 contributing tyers) worked very hard over the course of several years to get that final result.
Mark, just finished my tying last night for Loreto. Included several of your great new patterns. I also tied up six Calamarko Squid. I have been reading about Dorado gorging on squid so I am excited to have that great pattern in my box. I am psyched to try the squishy fly as well. Thanks again for another great book. It helped me a lot in my preparations. Have a couple of Mike Croft's big marabou Sardinas that he showed us at PSFC. I am also well stocked on Captain Skippy's Chico Carnada and Ghost Carnada. Have a couple of dozen great Shock n' Awes tied (Thanks Anil!) Now we will just have to get them in front of some fish.
Best regards, Steve