The size of the draw die radius is one of the major factors affecting metal to draw properly. If the radius is too large, wrinkles will occur on the part. If the radius is too small, it will restrict the flow of the material and cause cracking to the part. As a general rule, three (...
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Any tool maker might imagine what will happen if a tap within a progressive tool drives into a strip without a pre-pierced hole or a missing extrusion hole. The consequences can be very frustrating. The missing hole in the in die tapping tool ( IDT) can be due to some of the following reasons:-...
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A Faston connector is a conductive device that joins electrical circuits together. This connection might be temporary and could be disconnected quickly. The Faston connector has a wire crimped to the end while being connected to other electrical devices. The Faston connectors have been commonly used since the 1970s. It is economically cheap, thus,...
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Coining is a common process in metal stamping industry. It involves thinning the material thickness and transforms the piece part to completely new shape and size. Coining can be done by cold and hot process; it requires higher operational force and may need to be performed two to three times in order to form...
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As a tool maker for a few decades, I never know how a gold chain is made until I watched the following video clip. Thanks to the up loader! Watch carefully, the robot arms which are twisting the gold chains is actually similar to a multi-slide mechanism.
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Found the following chart from the Internet. I thought it is a good idea to share this piece of information with my Blog readers. This chart comparing the toughness and wear resistance of some common tool steels such as A-2, D-2, L-6, O-1, S-7 and H-13. It provides a guide to the tool designers...
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Pinch trimming operation is commonly used in deep draw progressive tool to separate the drawn product from the progression strip. Unlike a conventional metal cutting process, no shearing or fracturing takes place in pinch trimming. Because the metal basically is pinched off, a very sharp burr usually remains on the drawn part; this burr...
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To develop the flat blank contour of a drawn corner for rectangular drawn shell is not an easy task and there isn’t any formula that will produce a flat blank corner contour exactly conform to the print. Extra material will always produce at the edge near the center-line of the drawn radius; this is...
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Some readers wrote to me asking what is the best, recommended bend radius for cold rolled steel after reading my previous post, entitled “Good way bend and the bad way bend” while some engineering students from India asked for formulas for tooling design. P.S: It is highly recommended that, readers put their questions and...
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Side cam design is a common feature in tool making industry which could be applied on almost every tool that requires side cutting, side forming, clamping, rolling etc. Some mathematicians said the best side cam angle is about 43 degrees. At this angle; friction produced between both the contacting elements is reduced and thus...
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