A while ago, I wrote about how to make a metal stamping die, and therein, I shared my Do-it-yourself steps for the entire process. And perhaps I should also offer a few tips for metalwork and stamping to produce the best quality stamping products. Metal stamping isn’t usually a cup of tea but a craft to master, considering the essentials needed.
It’s always critical to use stable work surfaces to avoid shadowed impressions. Besides, annealing your blanks to prevent tears and breaking and opting for circular metal blanks will create a seamless metal flow. Using a few professional simulation software to develop designs will help you with the correct dimensions to work with.
As a metal stamping expert, I have adequate experience to help you make your metalwork and stamping process more seamless. Here are the tips from my many years of experience in the industry you can use for the best metalwork & stamping products.
Your Choice of Metal Blank Sheets Matter
I’ve worked with lots of metal blanks in my stamping operations, and ideally, I’ve observed that the punching pressure can be too much for some. However, you shouldn’t only opt for the stronger and thicker ones that might make the stamping strenuous. It all depends on your preferences and the scale of operation.
If you’re doing a custom DIY stamping on a small-scale using hydraulic presses by hand, you might want to stay away from thick alloy steels. Instead, pure copper or aluminum blanks can be ideal since they’re malleable and incredibly flexible. However, if you’re using industrial-scale dies and immense pressures, you can opt for blanks such as metal alloys. These are
Choosing the suitable material helps you acquire accurately stamped products with the right indents and dimensions. Also, ensure that you work with the best gauge, and if you opt for thicker blanks, 20-gauge sheets are fitting. A 24 gauge, thinner metal sheet can be ideal for light stamping, including hand DIY stamping.
Anneal Your Blanks
Annealing improves the workability of material, its machinability, and ductility. Some sheets can be tough to work on, being too brittle and highly susceptible to tearing and breaking. And if you don’t match the punching pressure, there’s a high chance of risking deformations and permanent distortions.
Metals have the uncanny ability to change their physical capabilities when acted on by heat. You don’t need an annealing furnace on a small-scale DIY project if you’re doing it. Instead, you can only use a propane torch and heat the blank just about shy of the melting point. Then, you let the metal completely cool down before using it.
Annealed materials are less resistant to punching forces and will flow seamlessly. Square blanks will benefit more since they tend to have lousy metal flow when stretching and can ripple or tear at the corners. If the material structure’s resistance to movements is less, you won’t have to deal with torn or broken blanks.
Leverage Simulation Software
It’s possible to make your dimension guesses almost off the top of your head. However, to acquire a high precision level, you must be well versed, or your stamping products won’t be highly competitive. But if it feels like an uphill task and mind-boggling, or perhaps, too much for your head, you can work with a few professional simulation software.
I prefer using software for two good reasons: they accurately estimate the blank size depending on how big or small you want your stamping products to be. Besides, they’re cost-free and tag along with computer-aided machining (CAM) features, having all the perks of an ideal stamping product. That way, you only feed it with the specs of your desired stamp product dimension, and it does the rest of the legwork for you.
If you have a software preference, you can always run to it. However, Fusion 360 usually bundles 3D modeling and CAM machining, which can be a better option. Remember, innumerable go-to software can get the work done for you. And while you may have a preference for one, try experimenting to get the various tastes and capabilities of others. Simulation software such as AutoForm and ESI-PAM STAMP can still be ideal.
Work with Optimal Temperatures
It’s pretty straightforward to predict the outcome for varied operation temperatures. On the basic principles of metal responsivity to heat, it’s apparent that metals experience marginal increases in lengths and sizes, which sometimes miss the eye. And metal stamping – as much as I Know it – requires no dimensional alterations that give different results from the projected ones.
Tinier expansions interfere with the offset measurements, leading to excessive punching pressure that won’t allow the blank to wiggle slightly. An offset is the metal thickness you “remove” from one die (either the positive or negative die). As the punching die deforms the blank, it shouldn’t press against it but allow some room corresponding to the blank’s thickness. And if you’re using low-gauge sheets, ensure that you get their thicknesses before including them in the offset measurements.
Stamping machines sometimes produce too much heat due to their innumerable moving parts. And if so, it can also affect the lubricant viscosity and render them ineffective. Some stamping machines, including most Grimco Presses and Trinks Inc models, have temperature gauges to indicate the heat levels. And for those that don’t, you can still use thermocouples to get accurate measurements for readjusting.
Lubricants are your best bet at minimizing friction and constant heat generation that tamper with the measurements. And while you can use lubricants on the punching dies and blanks, you also need to check for any beat-generating moving parts. That said, it’s not necessary to use the same type of lubricant on the entire machine. See what works best for each component and function before settling on them.
I usually prefer water-based lubricants since they’re less viscous and don’t cave in to marginal temperature upsurge. However, oil-based varieties can still do the trick but can be highly selective and task-specific. Some lubricants are compatible with only a few operations like drawing or light stamping, and others are cross-cutting. Such types are suitable for tinier budgets and can be your go-to’s.
Lubricants also play a massive part in keeping your stamping machines in perfect shape. Typical stamps are creations of various metal combos, and at some, the highly corrosive iron parts, including screws and joints, will tag along. That makes the machine vulnerable to rust, and corrosions can compromise its functionality. Lubricants usually form a protective coat to prevent the machine’s predisposition to rust-favoring conditions, including exposure to air and moisture.
Custom Finishing on Stamping Dies Saves Time and Effort
Creating metal stamping products is one thing, but getting them accomplished with functional features and aesthetic touch is another. Dies aren’t all the same or have similar surface finishes. Besides, you can still customize yours, providing countless options, leaving you spoiled for choice. And again, the type of surface finish depends on the purpose of the stamp, so it helps to know what you want precisely.
You don’t have to engrave the metal separately if you can do that right away as you punch and deform the blank sheet. You can ask your stamping die manufacturer to customize them and include your company’s logo or catchphrases, or perhaps the model numbers. That should save you the hassle of bundling different operations.
Understand the various types of surface finishing available before opting for one. If you prefer matte surface finishing or less shiny variations, ensure that your stamping dies mirror the same. That should get the work done in a single punch and save you the production costs.
Have a Few Extra Blanks for Errors
Most people venturing into metalwork and stamping operations don’t have adequate experience, and understandably so. There’s always more than what meets the eye, and while it may seem like a labored press-and-shape operation, there’s more that goes about behind the scenes. That includes making the right die and temperature measurements, opting for suitable blank materials, and gauging the punching force.
I’ve been there before, and during my early years of metalwork and stamping operations, there was a high possibility of making errors. And to compensate for that, I let it go easy on myself and stopped punishing myself for the mistakes. However, I had to invest more in materials since I more than once came out with improperly deformed products that were out of shape.
Therefore, it’s always prudent to have a few extra blanks for your trial and error. And please be conscious of how you make the minor improvements because if you don’t see any signs of progress, you might be doing things wrong. Don’t mind putting a dent in your budget if you’re learning something or two.
Curve Off the Offset
While I’ve hinted at offsets a little bit above, I’ll offer more insight. An offset allows you to stamp your blanks without scratching or brazing them, ideal for high-quality finishes. As your punching die exerts maximum metered pressure, it should allow some little room to accommodate the blank and not press it against the lower die.
It’d help if you carved out a fraction of an inch from the positive or negative die. You don’t have to curve both sides of the die since it might double the space and you want your die to grip your blank marginally. Doing so might leave more room for the blank to wiggle around and lead to a low-quality product.
Remember to include the offset in your measurements as you curve the die during your preparations. The only problem is that you might have to create a few more dies for various sheet metals having varied thicknesses. But if you’ll choose consistency, you can work with a single blank thickness to save yourself a few dimes.
Check the Pressing Speed
The pressing speed is as essential as all the considerations in metal stamping. Remember that you’re shaping metal and just some piece of soft cheese. And here, you must use some force – and not some mid-tier pressure. However, you must understand the speeds and cherry-pick the most suitable for the best metal stamping products.
Here’s an essential tip: don’t go all quick, but instead, take a breath. If you ram the blanks with supersonic speeds, the stamping won’t yield the best results. Instead, do it gently and ensure the punching die reaches the dead point. Most metal stamping machines have the functionality to vary the speeds, and it should be pretty straightforward. However, that might be challenging if you work with a custom die stamping.
As a rule of thumb, don’t ram fast if you’re using a small-scale DIY hydraulic press. Perhaps, doing a trial and error experimentation might bring you up to speed with the best paces to use. But keep in mind that similar metal sheet blanks respond to pressure at different rates, especially when the temperature isn’t constant. And if possible, try keeping it at a constant.
Take Care of the Draw Ratio
The draw ratio determines how good the metal flow would be. The margin out of the blank’s radius is left when the blank’s central region gets drawn in the negative die during the punching. Besides, this extra space usually trimmed out provides an extension for the blank holder to grip on.
The more expansive it is, the better. However, overdoing the lengths can badly interfere with the flow and result in below-par metal stamping products. If the draw ratio is significant, it might allow you to perform draw reduction as you look at shaping the stamping products.
The metal stamp is an art that requires a technique and know-how. More often, people end up with low-quality metal stamping products. And most cases, the machine work isn’t always the culprit, but a lack of a few essential tips might be the problem. As a metal stamping manufacturer with vast experience in metalwork, I’ve learned my lessons through trial and error, and I hope my experiences will be your eye-opener.