Re: Use of Star Washers for Ground Connections

I am among the "Stars" on this one too. Star washer has multiple points of contact v/s single point with the split washer.

As nuts as it sounds any mechanic can tell you for decades GM insisted on placing an inside/outside tooth star washer on the negative battery cable between the cable lug and the alternator mounting bracket.

But then GM pioneered the use of copper plated aluminum battery cables. With side terminal group 72, 74 and 77 batteries and alternators that used the Delco 1116405 voltage regulator with a 15.0 volt set point. Yeah, aluminum slapped up against a battery terminal. Battery cable replacements like Deka and Whittaker, made a fortune.

Johno02 wrote:
Star washer is to help keep the connection tight, not to provide better connection, although it probably does. Primary is to make sure you have a good connection, then star washers help keep it tight.

X2

The star washer is nothing more than a "lock washer".

I would be a bit concerned about placing the star washer in between the ground and the wire terminations, especially if it is OUTDOORS like a trailer frame. The star fingers will allow moisture to find its way between the termination and the frame and in high salt areas like ocean side or in the rust belt in winter will eventually result in a corroded connection.

If you must use a star washer, then put your termination dirctly against the steel frame, then add a PLAIN washer, then your star washer and nut.

On outside connections, paint the termination after you have torqued it to prevent corrosion.

I have made many a frame rail connection...

• For ultra critical "grounds" I scrape and wire brush the steel until it is bright
• Lugs to be stacked should look brand new bright
• I prefer to solder my lugs to copper cable wires
• Connection must remain tight and I mean very very tight
• So I use a bright bolt, nut, flatwasher and choice of nylock ring or stover distorted locknut
• Torque nut and bolt using torque wrench tension measurement
• Specs for each diameter are easy to find on Google
• At the last I spray both sides of frame rail with spray undercoating. A few coats.

Such protection can be submerged in salt water repeatedly and incur no damage. For decades.

Parts and hardware stores sell cylindrical shaped power wire brushes with 1/4" post and the steel wires of the brushes can be rope twisted. This makes cleaning a frame rail a snap. Rope twisted brush cups are aggressive. Take it easy around delicate stuff.

Properly applied undercoating or Wal-Mart truck bed undercoating is a forever fix. So I usually make a service loop of cable so the far end of the cable opposite the frame rail can be lopped off.

Overkill? Oh hell yes.

No worries, ever? Oh hell no. Absolutely bulletproof.

Place the terminals under the bolt head on one side of the frame. Place a flat washer on the other side next to the frame, lock washer next followed by the nut. Lock washer can be eliminated if using a self-locking nut.

For a threaded hole connection place lock washer under head of bolt followed by a flat washer with terminals next to the frame.

Star washer is to help keep the connection tight, not to provide better connection, although it probably does. Primary is to make sure you have a good connection, then star washers help keep it tight.

x2 good info.

Expose to bare metal and coat with battery terminal protectant after assembly. No real need for a star washer.

Most of the time, the "star" washer is used because the product manual realizes that most people will not scrape/grind the paint off the metal they are securing it too. The Star washer scrapes thru the paint(hopefully). Doug

For a high current connection you would NOTuse a star washer in the path of the current. It reduces the cross sectional area which increases resistance.

You want bare metal to bare metal with a light coating of No-Ox to prevent corrosion..

You can use the star washer or a split lock washer if you want.