Machine Screw Improvement (?)

This is where "feel" comes into play.

If you cross thread a bolt or screw, it's more than likely your fault.

Generally, if you feel resistance to rotation after 1/2 turn, STOP.

The lead thread will usually engage, or not, within the first turn.

Alignment is important too but just don't force it. Back up and start over.

An unthreaded lead might help.

Cross threading is not my issue...

Sometimes it is even getting the screw to find the threads!

That also works well for large diameter fine pitch threads where it is very easy to cross thread the parts.

This is what I'm thinking of!!

Any idea of a source? I'm not even sure what to call it...

We were buying these by the tonne as specialty fasteners. The other end was a HiLo thread for plastic with a shoulder midway.

One suplier was "Auto screw company",but that was over 8 years back and in Aus.

Automotive uses a lot of these called "SEMS" screws. There are also other specials available.

You can goggle "spae-naur" and see the catalogue, and I also know that Fastenal can get them.

i thought SEMS were screws with pre-installed washers?

A true SEMS, yes. But there are some variations available.

Outstanding!! Just what I'm thinking...thx

truth is not a compromise has great advice,

Also on my car it has a number of these types of mounts that it was inaccessible, or very hard. Where if you use your hand there's no space for much else even tightening. The last I worked on my car, when I was reassembling it, I had to walk away.

Then I purchase a set of these forceps, ^{(or Locking Clamp Pliers as HF may call them)} @ HF.

I used them to hold the fasteners in place, using them I was able to see what I was doing not only with the fastener but with the wrench also and in less than a 5 minutes using these, all screws were caught and tightened.

Are those different from Hemostats? I have and use two or three different sizes.

I've used various types of hemostats for years. When I was young and broke I would ask my doctor for old sets. The first time I got a strange look and had to explain 'why' I wanted them. I guess there are uses other than surgery and holding small parts and getting in difficult places.

I had to look at the difference between forceps and hemostats. But are similar. But what I love about them, is the locking ratchet.

With the difference sizes of forceps/hemostats, you can lock onto a little screw squeeze it , I thought at first that the screw would shoot out and loose it. But it hung onto it beautifully. You could never hold it with your hands to place correctly and with this you can place it.

When I was at Harbor Freight, I purchase all the types and kinds they had.

I don't recall the sizes 3", 4" 8", 12 or 15"" and with the Straight Jaws, 45 degree jaws.

I highly recommend it for your tool box, but you already know that.

Yeah - I use forceps at home for my bicycle work. I originally bought them for electronic parts placement in the old discrete component / breadboard days. Just don't take them to work, unless you are in Colorado - co-workers recognize them as a tool used by potheads.

Electronic coomponents, yes.

As far as Colorado...

Wow, my first fist to Colorado was to Colorado Springs in 99. Beautiful place.

Went to the Garden of the Gods and came out at Manitou Springs. Nice little tourisy town with gift shops.

I took my Girlfriend there back in 2010 when her son was getting deployed to Iraq from Fort Collins. Didn't have time for it but we returned back there to visit some friends in 2014.

Of course I said to my girlfriend what a great little place this Manitou Springs was, that she would love it. got there and WOW,... head shops, unemployed musicians looking for an audience, acne scared 20 something's stumbling around looking for something that's not there. ya, I hear ya...

Not much help if you are rebuilding old equipment but, if you were designing from new, you could take the other approach & use a standard screw but counter drill the first few threads in the tapped hole to locate it.

I was involved in final assembly of landscaping equipment and the best results we had were with the piloted screws that Solar showed in his post. Additionally, we did counterdrill threaded holes for about 3 threads depth to guide on the OD of the screw threads. The pilot on the screw was just slightly less than the tap drill of the threaded hole.

In assembly, you got one click as the pilot dropped in, a second click when the od of the screw dropped into the counterdrill and then you were 99.9% lined up and ready to tighten. We were using magnetic tip JIS cross head drivers in torque controlled screw guns. We had final assembly of string trimmers down to about 120 seconds per trimmer and as low as 90 seconds on a good day. That included installation of the engine, connection of the throttle and ignition, installation of a handle and packaging the finished unit, a total of 15 screws in 3 sizes.

Try Lee Valley--They have a finger, glove type mechanism, that contains a small rare-earth magnet that holds the nut in place, on the backside, out of visual range, while you "feel" the bolt or machine screws into it from the front. Works great.

That'll only work for magnetic nuts. I use a lot of brass and Stainless, so the Hemostat commonly does the job.

These work for any material, I've had a set for years for those tight situations.

Interesting! I hadn't seen those. Are they available in the USA?

That's how it's done on race cars.

Sizes:

Jolts are measured by, string and length in a specific order. Much of the time, distance across and length are recorded in inches, and string in strings per crawl. Along these lines a one-fourth-crawl width dash, with 20 strings for each creep, two creeps in length, would be recorded as a one-fourth creep x 20 x 2 crawl or quarter/20 x 2 creep.

Once in a while, strings are recorded as UNF (fine) or UNC (coarse) rather than per creep. Only a little variety to keep things intriguing.

Why have distinctive sorts of strings? Fine strings make a more grounded jolt that can be torqued up more tightly than a dart with coarse strings. They are additionally better on littler jolts. Then again, coarse strings are harder. They'll hold better in high-wear circumstances, or when you may need to evacuate or supplant the jolt as often as possible. They likewise oppose cross threading superior to anything fine strings.

On the off chance that you need to purchase a fastener to fit a particular nut, bring the nut with you to the store and ensure you can string it onto the screw you purchase. String it the distance on. Infrequently a nut will go on a turn or two regardless of the fact that it doesn't coordinate the string of the fastener.

I have some information to share out about screw

About size / design / function

Our can read over here---->http://crbtech.in/CAD-CAM-Training/designsizefunction-screw-conveyor

thank you