sheer pin question

[brian]

Is grade 8 3/16 rod good enough to use for sheer pins?

What are vrp sheer pins made out of?

How hard are the aircraft pins?

[crankbearing]

Shear Pins Strength

Hey B,

I have some 3/16 x 1" dowels that I bought locally and they are hard if you tighten too much you will snap them in half.

The aircraft rivets are actually softer they give a little (flex) when tightened and loosened several times. I have a buddy that runs a season on one aircraft rivet against my better judgement.

The steel rod I have tried before and I can't remember how it faired out, but I think that I would go with the rivet from Jerry Nieses for the price you can't beat it. I pay $10CDN for 10 bolts locally at the beginning of the season.

Regards,

[Jack Stotts]

I use 3/16 stainless steel rod and have run the same pins for about 2 years. I get the rods at a model airplane shop and cut them to length. They do bend a little when I tighten the prop nut but that keeps them in place. Have never sheared one. I run them on Y-80, Y102 and on my CMod. I simply hit them with a hammer on a flat surface to get the kinks out when bent.

[FL47F]

I think I'm using the same as Jack, only difference is I get the rods at Home Depot.

[brian]

I have sheered the aircraft in my 44 (maybe 2 in 3 years) and this year it looks like I will have an FEH so I do not want to miss a heat due to a pin.

The pins Steve L. uses and sells come from VRP and they hold up well but we don't know what they are hade out of.

Just looking to be ready in May and want to race till the cows come home!!!

VRP website, email?

Brian

[Dave M]

Shear Pins

I use the Yamato Hatchet Unit (same as VRP Basically). The stock shear pin hole is 5mm, I drill out to 6mm for FE. I use Grade 5 Bolts fromt he local hardware. I grind down one side of the head so it does not hit the prop on its way in. And I also put a nut on the other side. Craig always tells me I am killing him, but it works and I rarely shear them like I have all the other stuff, meaning aircraft rivets, etc. With the 44 I think it is fine, but with the FE and the difference in Torque, I would bolt it.

My two cents.

[39R]

I've been using Mil Spec SS dowel pins on my Y102 & 44XS that I heard about in this forum last year. I order them from McMaster Carr. I raced all last season on just few without any problems at all.

Here's the information: http://www.mcmaster.com/

1 PK 98380A510 - Type 416 SS Dowel, $5.40 PK, Pin 3/16" Diameter, 1" Length, MIL Spec 16555-643

1 PK 98380A512 - Type 416 SS Dowel, $5.86 PK, Pin 3/16" Diameter, 1-1/4" Length, MIL Spec 16555-644

[brian]

Music wire?

I am hearing good thins about 3/16 music wire. anyone have any pros or cons? I guess it flexs but just does not break.

Brian

[brian]

416 not rated for sheer strength

Type 316 Stainless Steel—Slightly magnetic with better corrosion
resistance than 18-8 stainless steel. Not passivated. Rockwell hardness is B85. Not rated for shear strength. 18-8 Stainless Steel—More corrosion resistant than Type 416 stainless steel and slightly magnetic. Not passivated. Rockwell hardness is B85. Not rated for shear strength.

Hardened Steel—Made from hardened steel such as C1541 steel and 4037 and 4140 alloy steel. Meets ASME B18.8.2. Rockwell hardness is C47-C58. Single shear strength is 130,000 psi.

Unhardened Steel—Also called shear pins. Made from unhardened 12L15 steel. Rockwell hardness is B50. Single shear strength is 68,000 psi.

[David_L6]

I use shear pins intended for the old 18, 20, 25 hp pin drive OMC motors (I think they are sold as a number 10 - I'll get the number off of a package and post for sure later). You can get them at almost any marine dealer (like in McAllister, OK on my way to Stigler, OK! ). Around here I buy them in a 2 pack, but they are also available in a bag of 10. I use them only once usually. I have straightened and re-used them, but I really don't like to do that with the 44. I feel a little more comfortable re-using pins in a C, but not much.

I hate to say this as I'll probably jinx myself, but in 20+ years racing I don't remember ever breaking a shear pin in a heat and all I've ever used are the above mentioned OMC pins and some "aircraft" bolts. (The bolts are too hard to find to suit me. I need something that my forgetful self can buy anywhere on the way to or at race site!)

[brian]

416 not rated for sheer strength

Type 316 Stainless Steel—Slightly magnetic with better corrosion
resistance than 18-8 stainless steel. Not passivated. Rockwell hardness is B85. Not rated for shear strength. 18-8 Stainless Steel—More corrosion resistant than Type 416 stainless steel and slightly magnetic. Not passivated. Rockwell hardness is B85. Not rated for shear strength.

Hardened Steel—Made from hardened steel such as C1541 steel and 4037 and 4140 alloy steel. Meets ASME B18.8.2. Rockwell hardness is C47-C58. Single shear strength is 130,000 psi.

Unhardened Steel—Also called shear pins. Made from unhardened 12L15 steel. Rockwell hardness is B50. Single shear strength is 68,000 psi.

[David_L6]

Brian, I'm kinda slow

Ya wanna interpret all that?

[brian]

David,

Wow I know how you feel that is why I posted it.... Maybe we can get some answers or just a I use that and it works.

B

[Kermit SST45]

I use Drill Rod ran it in my D stock and currently use it for my SST45. It can be bought through McMaster-Carr. Use the "find" box and type in drill rod, the "Grade A-2 Air Hardening comes in almost any size and 3' lenghts. Prices around $5.00- $10.00. You can cut a lot of pins from a 3' stick.

[Merc1]

Shear pins

Call Jerry neises, the pins he is selling should work just fine and why do you have to use a 3/16 pin why not use 1/4? also just use one pin per heat if your concerned about breaking them. they are cheap and easy to change.