Stainless Steel vs. Brass Threaded Inserts for Plastic

The Benefit of Brass Threaded Inserts

Brass threaded inserts for plastic and 3D printing thermoplastic applications are typically slotted to minimize splitting or splintering. As mentioned, when comparing stainless steel vs. brass threaded inserts, most manufacturers agree that brass is the better option for a wide variety of reasons. That being said, let's get into some of the benefits that come from using brass inserts over stainless steel.

First, brass threaded inserts offer greater thermal conductivity than threaded inserts made from austenitic stainless steel. In fact, brass inserts are typically 15 times as conductive as stainless steel inserts, meaning brass is optimal for heat and ultrasonic installation methods. Good thermal conductivity also translates to an installer having better positional accuracy when setting brass threaded inserts for their project. Brass also cools quickly. Installers can have better peace of mind knowing that brass threaded inserts can be set promptly and accurately in components without the inserts moving within the plastic hole and compromising the entire project. Compare this with stainless steel inserts, where installers must brace the steel insert within the molten plastic after it is put into position, so it doesn't "float" around in the hole, compromising the joint integrity of the finished assembly.

When comparing brass and stainless steel, it's also worth noting that brass threaded inserts are much more valuable than stainless steel inserts. As a result, manufacturers can recover more material costs after manufacturing if they choose brass inserts. Brass threaded inserts also possess great strength, allowing solid and durable holds. When an installer wishes to make a threaded part stronger, they only need to increase the thread length of the brass threaded inserts to avoid the higher cost of stainless steel.

Other benefits of brass threaded inserts include resistance to exposure from mild alkaline solutions and corrosion in non-oxidizing acids and petroleum products. However, installers should avoid strong alkaline solutions such as hydroxides, cyanides and oxidizing acids.

The Benefit of Stainless Steel Threaded Inserts

Although stainless steel inserts are appropriate for use in some projects, it's often somewhat unnecessary. When deciding to use stainless steel or brass threaded inserts, brass usually satisfies most requirements at a better price. That being said, stainless steel threaded inserts carry benefits of their own which may be more useful to installers.

Stainless steel threaded inserts are available in more varieties than brass inserts, though 300 series and austenitic stainless steel are the most common forms an installer will find on the market. When thinking of stainless steel vs. brass, the properties of stainless steel inserts vary dramatically from one alloy to the next, making it more challenging to generalize their benefits. However, stainless steel threaded inserts offer excellent resistance to petroleum products and most acids. Though installers should avoid hydrochloric acids, stainless steel inserts can easily be passivated in either citric or nitric acid solutions.

Stainless steel inserts can also provide higher strength than brass threaded inserts depending on the grade/alloy used, giving projects a more durable hold and better resistance to vibrations.