Hardness for fasteners used in medical device

As we have mentioned earlier in previous article that the fasteners commonly used for medical parts are stainless steel, but how to select the type of stainless steel license plate also involves the matching of hardness.

If you want to driving directly into the workpiece in your process, the fastener needs to be harder than the target workpiece. Therefore, there are plenty of options, from carbon steel to stainless steel to titanium, which can be purchased when choosing micro screw for plastic parts.

However, when the target workpiece is metal, the comparison of hardness needs to be fully considered in advance. Fasteners are sometimes used in multiple combinations, and the matching of materials is also to meet the mutual matching of hardness. For example, if a nut is manufactured in SUS316, but the screw is manufactured in SUS 303, then the screw will prematurely fail, necessitating the replacement.

Since 304 and 316 cannot be heat treated, if more stringent requirements are met on hardness matching, materials such as precision hardened stainless steel can be selected.