So I'm assembling a pull up bar and its assmebly instructions look like this
In the parts list it mentions only one type of spring washer (quantity 4).
But it actually came with two types of washers (quantity 4 each), type1 and type2.
Am I supposed to use both of them? And in what way? Any help would be appreciated!
They gave you four lock washers instead of 4 locking nuts. No problem. Install the bolts as shown in the instructions. Then install a flat washer on each bolt followed by a lock washer and then the nut. Tighten as specified.
Put the flat washer on first then the split lock washer and finally the nut.
The advice from the German military shock testing establishment is to NEVER use any washer except a flat one.
It is the bolt that should be under tension and the bolt that provides the force that keeps the joint together. Spring washers, split washers and crinkle washers will eventually yield and the tension in the bolt will be lost. The joint WILL open up. At best the nut will fall off, at worst the bolt will experience shear or bending moments and fail.
They are normally installed so the split-ring "lock" washer is against the nut, and the flat washer is between the split-ring washer and the surface. This is to prevent damage to the surface. It appears they did not provide any flat washers, is that correct?
It appears they provided locking nuts, the kind with a piece of nylon or fibrous material in it. So you should be good.
However, I'd like to add some content about split-ring "lock" washers.
Both the Germans in the (I think) 1930s and NASA in the (I think) 1960s determined that split-ring spring washers, aka split-ring "lock" washers, actually speed the loosening of a nut under vibration when no other method is used of locking the thread in place.
This link contains quotes and a chart from the NASA paper. The chart on the last page is quite illuminating. http://hillcountryengineering.com/wp-content/uploads/2011/10/Split-Lockwashers-Separating-Myth-from-Truth.pdf
If you want a deeper read, here is the 100 page NASA Fastener Design Manual. https://ntrs.nasa.gov/citations/19900009424
I got the same exact diagram for my pull-up bar, listing parts
#1-11 and split washers were included additionally.
Accidentally, I assembled the pull-up bar without the split washers, only noticing the split washers after finishing the assembly with the flat washers. Nevertheless, I have been successfully using the pull-up bar at home for 3+ months with no issues. May tighten the bolts after a year use anyway.
