Mini Case Study: Palbit Tooling Helps Marine Propulsion System Repair Shop Achieve 3X DOC and 35% More Feed in SS Turning Application

We recently worked with a New England company that specializes in repairing and refurbishing propellers and inboard driveshafts for applications ranging from five-horsepower outboards to deepwater boats such as fishing trawlers, tugboats, ferries, and Coast Guard vessels throughout the Northeast.

The company's recent acquisition of a DMG Mori NLX4000 lathe with live tooling capability has enabled it to offer new shafting up to 7-in. diameter and 30 ft. or more in length. These shafts are typically made from Aquamat 17 or Aquamet 22, marine-specific grades of stainless steel noted for their high strength and corrosion resistance.

While there are many carbide insert manufacturers touting the high-speed performance of their grades and coatings, the company required an insert that can also perform at low surface footage, because of the RPM limitation dictated by safe rotational speed for those 4,000 lb-plus shafts.

The company had been using Products from Seco Carboloy and Kennametal at lower than recommended speeds, resulting in chip control difficulties, primarily bird-nests of chips at low depth of cut and feed per tooth, or catastrophic insert failure when trying to break the chip at increased depth of cut and feed rates.

A new product from Palbit, the CNMG-432 insert with SS chipbreaker in Grade PHS225, was offered for comparison by Palbit's local distributor. In a recent trial, a representative from the distributor, the manufacturer's rep that works with the distributor, and our own Palbit specialist, Cody Gadreault, were on hand to assist and offer recommendations on cutting parameters. This insert proved to be highly effective for stainless steel turning, increasing DOC by 3X and feed rate by 35%. It also allowed chips to be broken into classic sixes and nines while enabling unattended and uninterrupted operation.

The customer looks forward to applying these inserts at their higher recommended surface footage and feed rates on chucked parts, where RPM is not limited by the safety hazards presented by a long rotating shaft.

Pilot Precision Products helped the customer boost performance with Palbit inserts, and we can help you, too. Reach out to see how we can support your next stainless steel turning application.