Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Graphite, Lubricants, Metals
Name: Robert S. B.
Status: educator
Age: 40s
Location: N/A 
Country: N/A
Date: 10/2/2004


Question:
Does graphite "bond" to metal? My son is doing a research paper on "What is a better lubricant for skateboards, graphite, WD40, or motor oil". I am looking to find out why people do not normally use graphite as a lubricant when it is such a good one.


Replies:
No, graphite does not bond to metal in the conventional sense. Graphite sticks modestly well to many substances if you rub or burnish it on. Note that graphite is corrosive to aluminum in the presence of moisture.

Graphite is what is called a "solid lubricant," and it is a solid that is slippery. Other solid lubricants include molybdenum disulphide, PTFE (that is the chemical name for DuPont's Teflon (TM)), and hexagonal boron nitride. Graphite needs humidity from the air to be slippery. Like all lubricants, it has advantages and disadvantages depending where and how it is used.

Things you could investigate when comparing lubricants could include: 1) which material makes rolling easiest for light and heavy loads, 2) which material keeps lubricating in the presence of dirt, 3) which material works best to keep the ball bearings from wearing out, and 4) which material keeps the bearings rolling most smoothly?

Because skateboard wheels roll on ball bearings, the friction will be low. Also, commercial skateboards use ball bearings with seals on them to keep the grease in and the dirt out.

Bob Erck



Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory