Blow Bars: Getting the Most of Your Impact Crusher

close up view of metso blow bars

Whether you refer to them as breaker bars, hammers, or impact hammers, getting the most of your impact crusher comes down to your blow bars and your ability to use them well.

Depending on what you’re planning to crush – asphalt, limestone, or even if you’re recycling concrete – the type of blow bar you use matters. While it might take you a day to replace your blow bars, you can save time and money knowing the best blow bars for each job.

While the blow bars might look the same, the metallurgy will always separate each of the four main types of blow bars. From high chrome to hybrid, each blow bar has a specific purpose that needs to be chosen based on many variables such as feed size, geology, and tonnage.

Regardless of what you’re looking to crush, one of these types of blow bars should fit your need.

High Chrome Blow Bars

If you’re looking to crush asphalt or other types of highly abrasive materials, you’ll want to focus on using high chrome blow bars. High chrome blow bars are a bit more brittle in comparison to the other metallurgy so it is best they are used for rock crushing only. Also, it is important to maintain a smaller feed size as to not cause too much continuous dramatic trauma which can cause cracking. The biggest concern here, however, is making sure all tramp metal is kept away from the high chrome blow bars. Too much steel or steel that’s too large can cause the bar to fracture. If properly maintained and used only for crushing rocks, high chrome bars will last the longest without having to be replaced.

Medium Chrome Blow Bars

Medium chrome bars are not as vulnerable to tramp events, but it is still a good idea to make efforts to keep these instances to a minimum. Since it’s a little more forgiving than high chrome bars, medium chrome is best for crushing a variety of materials. Using medium chrome bars also gives you the advantage of your crushing handling a larger feed size. While this type of bar can do some work with asphalt, it’s not a good choice when it comes to recycling, or Reclaimed Asphalt Pavement (RAP), jobs.

Low Chrome Blow Bars

When you need to crush just about anything, low chrome blow bars are the way to go. Low chrome bars are ideal if you’re working primarily with concrete, demolition, and aggregate jobs. This type of bar is the most forgiving, so it stands up well to very large feed materials as well as feed that is heavily contaminated with steel and rebar. This particular bar, however, would not suit you well if you needed to crush highly abrasive materials. Low chrome blow bars can take a serious beating, but what you gain in resistance to fatigue to traumatic events you lose in wear life.

Hybrid Alloy Blow Bars

A hybrid alloy blow bar is very similar to a high chrome bar, even though the metallurgy is different. This bar is a good fit for operators who are crushing materials that are abrasive, such as asphalt, but may need the ability to handle larger feed sizes. This bar can also work for operators who may need to crush concrete or light aggregate on occasion. As with high chrome bars, any type of tramp metal should be removed, especially if it’s large.

Care for Your Blow Bars

In order to get the most out of your blow bars, it’s important to use them properly. The wear life of your blow bars in a quarry scenario will vary depending on what stone you are crushing and the volume and frequency in which you are crushing it. At the same time, if you are a contractor and you deal mostly with recycled concrete and asphalt your needs will be much different because of the greater the possibility of a tramp event. When you use the proper bar, you’ll get more life out of it.

Since many facilities don’t carry excessive blow bar stock, it’s vital to make sure to monitor the condition of your bars frequently, especially if there is a tendency for tramp events. Once the bars are worn down, or damaged (cracked), you need to replace them as soon as possible. If you wait too long to replace your blow bars or neglect to regularly inspect them you could end up losing many valuable hours of production.

Don’t Wait Until It’s Too Late

The Mellott, a family business for more than 95 years, has the equipment, parts, and know-how to make sure your company continues to run at peak efficiency. We offer both new and used parts, as well equipment sales and rentals, service, and component exchanges.

Before your company needs new blow bars, be sure to look at what we have to offer. Visit us at or visit our new e-commerce website.