Harrison Design ignition sets are manufactured from top grade tool steel to provide precise fit and reliable, consistent function under the most demanding conditions. Each part is wire EDM'd and CNC machined for a precise +/- .0005" tolerance, heat treated to Rc 53 – 56, then honed and mirror polished to give Extreme Service in your pistol. The hammers are slightly narrowed to avoid unwanted contact with the slide or ejector. They have deep serrations to help you keep the hammer under control and all exterior corners are CNC machine beveled to minimize snagging and abrasion. The Concealed Carry hammer with its "teardrop-shaped" hammer hole has a rowel section (the Mfg: Harrison Design & Consulting