Production Machining

JUN 2018

Production Machining - Your access to the precision machining industrial buyer.

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Page 19 of 51

Helping Precision Machine Shops Be More ProducƟ ve and Profi table 18 PRODUCTION MCHINING :: JUNE 2018 than 350 different stainless alloys fi t into fi ve categories and what each category meant to us as machinists. Austenitics, for example, give the best corrosion resistance and are virtually non-magnetic, except by cold working, which is also the only way to increase their hardness. Types 303, 304 and 316 are the most commonly encountered austenitic stainless steels in our precision machining shops. Ferritic stainless steels are characterized by intermediate corrosion resistance, are magnetic and are hardenable only by cold work. Grades 409 and 430F are typical ferritic stainless steels. Martensitic stainless steels, typically grades 410, 420F and 440C, have relatively low corrosion resistance, are magnetic, and achieve high hardness and strength through heat treatment. 440C is typically specifi ed where high hardness (think 60 HRC) and some corrosion resistance is required. The fi nal group discussed was the precipitation hardenable grades, which were characterized as having low corrosion resistance, magnetic properties and are heat treatment hardenable. Ray says for best machinability, typically H 1150 M is the optimal treatment for our shops to process. Ray's conclusion gave all in attendance a nice overview of the multiple types of stainless steel we see in our shops, how machinability can mean different things to different people and that effi ciency is not always measured by the lowest cycle time. We are facing so many different options of materials, treatments, structures and processing options, it is wise to reach out for help rather than struggle with production. Carbon and Alloy Steels I reviewed how steel factors of chemistry, mechanical properties and our shops' processing can all impact the steels' machinability. Chemistry factors discussed included the role of carbon on mechanical properties, role of sulfur on machinability, as well as that of lead. Understanding how phosphorous and nitrogen can help with chip separation and surface fi nish and the role silicon and aluminum play were also covered. The benefi ts of cold drawing in regards to boosting mechanical properties were then discussed and the role of the yield strength to tensile strength ratio was explained for better understanding chipbreaking and machine power requirements. Shop processes can also have a major impact on how the materials process, starting with the role of purchasing, to better limit material variability and improve machining performance in the shop. There were a number of heads nodding and conversations started when this factor was presented. A review of the process of work hardening, why we should work to eliminate tool dwells and the need to maintain sharp tools were the fi nal takeaways. The use of a microscope to examine tools for wear patterns, built- up edge and other clues as to the voice of the process was presented as a best practice and concluded the prepared comments. National Technical Conference Recap: Metallurgy for the Non-Metallurgist Continued from page 15 Continued from page 17 4 Steps to Gain Control of Inbound Shipping routing instructions and sending them to all of your key vendors. This is where your 3PL partner will either impress or disappoint. A 3PL with inbound shipping experience will be able to help you create your inbound routing program with the following services: • Identify and manage lists of key vendors. • Create clear inbound routing instructions for each vendor. • Draft and send routing instruction letters to each of your key vendors on your behalf. • Monitor and report on vendor compliance. • Consolidate your billing and report to you the savings you are receiving through the program. Inbound shipping costs are a major expense item for many businesses, particularly when you leave the control up to each of your vendors. If approached correctly, an inbound shipping management program can be an easy way to reduce your overall transportation expenses. Inbound shipping programs are often best managed through a third-party logistics provider. A good 3PL can help you analyze your purchase invoices for savings opportunities, develop routing instructions for your vendors, monitor compliance and audit and consolidate invoicing to ensure you're saving the most on inbound shipping.

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