Why Carbide Mandrels Work Better for Neck-Turning
If you have ever turned a large quantity of case-necks using power assist, you know that a carbide mandrel can make the job go easier, with better end results. In our experience, when using carbide mandrels (as opposed to ordinary steel), the cases move more smoothly with less heat build-up. Pat Reagin of PMA Tool explains why carbide neck-turning mandrels work better:
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Carbide offers several advantages over conventional steel and stainless steel when making any tooling, specifically neck-turning mandrels: Dimensional Stability — Carbide maintains its dimensions indefinitely during heating and cooling. This eliminates the need to allow the mandrel time to cool every few cases. Coefficient of Friction and Wear-Resistance — Carbide exhibits a low coefficient of friction value as compared to all steels and wears up to 100 times longer. This reduces (but does not eliminate) the amount of lubricant required. Galling Resistance — Carbide has exceptional resistance to galling and welding at the surface. This basically eliminates the chance of getting a case stuck on a mandrel due to insufficient lubrication. |
Given the benefits of carbide neck-turner mandrels, you may be asking “where can I get one?” Sinclair Int’l offers carbide mandrels for Sinclair neck-turners for $49.99, in a full range of calibers: 17, 20, 22, 6mm, 25, 6.5mm, 270, 30, and 338.
$49.95 Carbide Mandrels from PMA Tool
PMA Tools now also offers carbide mandrels in a full variety of sizes. At $49.95 each, PMA’s carbide mandrels are priced competitively with Sinclair’s mandrels. PMA offers carbide mandrels in .17, .20, .22, 6mm, 6.5mm, 7mm and .30-caliber. These will work with Sinclair Int’l and 21st Century neck-turners, as well as PMA neck-turners. PMA tells us: “We now have carbide neck-turning mandrels in stock. These mandrels are made with high-tech CNC grinding-machinery, and should give you excellent results. We hope to be add other larger-caliber carbide mandrels to our lineup in the future.”













From PMA’s website I learned that this turner does NOT use a coarse or fine drive screw to move the cutter towards or away from the mandrel. Nor does the PMA tool move the mandrel on an eccentric (another method of cutting depth control). The PMA tool does something very different. PMA’s Model A Neck Turning Tool simply adjusts by moving the mandrel toward or away from the stationary cutter with an 80 TPI drive screw with 60 indicating marks. Each mark moves the mandrel .0002″ (two ten-thousandths). I found, if you stop between the marks, .0001″ isn’t out of the question. It’s such a smart arrangement, I wondered “why didn’t anyone think of that before?”





