What is a "case hardened injector pin"??

[rogerflies]

In the "Sagitta Fever" thread, Ollie suggested using a "case hardened injector pin" as the wing rod. What is it and where can I get one (or more)?

Roger

[Ben Diss]

John Kappus posted this in 2000 to the RCSE list:

"Ejector pins are often suggested for wing rods because of a combination of properties. They are typically H 13 steel (a very good grade) that has been heat treated to 40 on the Rockwell C scale. Additionally they are case hardened by Nitriding to a depth of .001-.002" The surface is 65-74 Rc which is harder than most files. This surface hardness, combined with the medium hard (but not brittle) core, give a very strong rod that will still bend before it snaps. They are manufactured in standard sizes and are never over the listed diameter and less than .001" undersize (+.000", -.001" diameter tolerance). (By the way, there is also a product called a core pin which is stronger because the pin is 50-55Rc, however it may have a brittle failure).

"Ejector pins are available from a number of manufacturers, DME and National being the largest. They are available in many cities from mold supply companies which may be listed in the yellow pages under Molds, Mold Tooling, or Tool and Die Makers Equipment and Supplies.

"Yes, they are available in metric sizes."

Here are a few sources:

http://www.skybench.com/
http://www.ntm.com <-- They have a min $25 order.
http://www.dixiepins.com/

-Ben

[Ollie]

http://www.dixiepins.com/
The case hardened injector pin is stronger and stiffer than musicwire. The core of the pin is much tougher and skin much stronger. The case or nirited. For the jointer, the head is cut off.

[johnsocj]

Don't forget the ubiquitous McMaster-Carr. (mcmaster.com)

Check in "shafts" many have similar properties to what you've described, and you don't have to cut anything off.

Online ordering is very easy.

C.

[nwoods]

I think perhaps the answer is more basic. They are specially made pins that hold the seats in place in fighter jets, that are removed explosively when the pilot bails out.

We use them as wing joiners, but hey, as long as they are in an airframe, they are happy, right? :-)

Nathan Woods

[Mark Miller]

Definition: A rod, pin or sleeve which pushes a molding off or forces it out of a cavity. It is attached to an ejector bar or plate which can be actuated by the ejector rod(s) of the press or by auxiliary activated cylinders. It is used in the molding industry.

Mark