What size bolts are these?

[coopec]

I've spent all the morning trying to get the "lid" off my Whitlock pedestal. Despite using penetrant and heat I only managed to get two off with the Allen Key. I ground the head (CSK) off the other two, lifted the "lid" then used vice grip wrench on the other two. One came out with a lot of coaxing and the other snapped off flush. I am now attempting to drill the broken bolt as accurately as possible and then I will tap the hole.

I want to order new bolts and a thread tap to re-thread the hole (with the broken bolt). My question is

• what thread they are. Being a Whitlock Pedestal they wouldn't be metric. Would they be British Standard Fine (BSF)?
• the diameter of the bolt is .190 and length is .624. The diameter is therefore 3/16" and length 5/8. What would the thread be? (Just looking at eBay now maybe they are " UNF Imperial Fine Countersunk"?)
• I'm inclined to reduce the length to 3/8" so I don't have this problem again. Would that be a mistake? Will a thread lubricant help?
• I plan to replace them with SS bolts

Thanks in advance

A FURTHER UPDATE I tried to drill the hole but as I half expected the hole is a bit oversize despite the fact I used a smaller drill. I thought I'd fill the hole with epoxy and thread into that. But is there a better product (maybe in the Loctite range)?
Maybe I worry too much as there are thre holes holding it anyway.

https://flic.kr/p/2imsuJ7

 

[Talulah]

To avoid the cost of taps etc I would be tempted to buy threaded inserts off eBay.
This will also resolve your oversized hole issue.

 

[coopec]

To avoid the cost of taps etc I would be tempted to buy threaded inserts off eBay.
This will also resolve your oversized hole issue.

I didn't think of that. Thanks

 

[Iliade]

or stainless steel Helicoils:
25083 | Recoil Thread Repair Insert, M8 x 1.25, Drill Size 8.3mm | RS Components

 

[Boathook]

Depending on the age of the unit the threads are likely to be metric. Are the sizes you have quoted inches?

 

[earlybird]

If your threads actually measure 0.190", they could well be Unified, there are 2 standard sizes for this diameter, referred to as #10-24 and #10-32, UN coarse and fine resp.
If Whitlock is of US provenance, unified threads are likely.
Threads never actually measure oversize, so yours, at 0.190" won't be nominally 3/16".

 

[Goldie]

Have you tried asking Cliff Mogridge - winchservicing.com ? He seems to be knowledgeable about all things Whitlock.

 

[coopec]

Have you tried asking Cliff Mogridge - winchservicing.com ? He seems to be knowledgeable about all things Whitlock.

I believe you. I just came up with his site.
Thanks for that

Whitlocksteering.com

This site is run by Cliff Mogridge, Lewmar / Whitlock agent and former Lewmar employee; based in Emsworth, Hants. U.K.

Whitlock Steering

 

[RichardS]

or stainless steel Helicoils:
25083 | Recoil Thread Repair Insert, M8 x 1.25, Drill Size 8.3mm | RS Components

That is what I would do.

Or, if the size is an old imperial size, then buy a tap set and drill and re-tap all of them to M8 (or whatever is the next metric size up). Plus use copper grease when you reassemble.

Richard

 

[Stemar]

I'm lead to believe that adding a third metal to SS in alloy can make corrosion worse. Would it be better to use Duralac or similar?

 

[coopec]

If your threads actually measure 0.190", they could well be Unified, there are 2 standard sizes for this diameter, referred to as #10-24 and #10-32, UN coarse and fine resp.
If Whitlock is of US provenance, unified threads are likely.
Threads never actually measure oversize, so yours, at 0.190" won't be nominally 3/16".

Thanks but I have verified that the pedestal was made in the UK,
And when they were referring to the diameter of the wheel they stated 30 inches (76cm)

So the bolts must be Imperial?

 

[lw395]

I'm lead to believe that adding a third metal to SS in alloy can make corrosion worse. Would it be better to use Duralac or similar?

Copper grease works. Don't ask me to explain how!

 

[coopec]

Depending on the age of the unit the threads are likely to be metric. Are the sizes you have quoted inches?

The unit was made in the UK (I found a label) And when they give a size they give it in inches and the metric in brackets.

Thanks

 

[lw395]

Thanks but I have verified that the pedestal was made in the UK,
And when they were referring to the diameter of the wheel they stated 30 inches (76cm)

So the bolts must be Imperial?

Not necessarily, mixing units is very common. We still buy our TVs in inches and bolt them to a bracket with metric screws.
Metric seemed to become common sooner in smaller sizes? Before that we had BA, particularly in electrical stuff.

 

[coopec]

Not necessarily, mixing units is very common. We still buy our TVs in inches and bolt them to a bracket with metric screws.
Metric seemed to become common sooner in smaller sizes? Before that we had BA, particularly in electrical stuff.

I think I'll take my pedestal to the local hardware and find a bolt that will fit the pedestal. Then I'll buy the equivalent in SS (whatever that is)

It hasn't been my day! Now I find the chain split links (although marked 530H) don't fit..... ( Fortunately the chain size fits the pedestal sprocket perfectly)

 

[Neeves]

And our yachts are still 'described in feet.

And ours a Lightwave 38 has both metric and imperial fasteners which damands two tool kits.

I'd do what you have decided - take the lot to a decent hardware store, or nut and bolt retailer, and ask them. If you lived a little bit closer I could tell you where to go here - but....

Jonathan

 

[sailorbenji]

Any idea on the age of the pedestal......if old enough, they could be Whitworth on a Whitlock pedestal.

 

[coopec]

Any idea on the age of the pedestal......if old enough, they could be Whitworth on a Whitlock pedestal.

It is unused but probably 20+ years old. Does that give you a clue?

It is stiff as hell to turn so I'm going to have find a maintenance manual (but I suppose it is quite straight forward).

 

[doug748]

2BA has an outside dia of .185''

TPI of over 30tpi. So if it looks pretty fine, next to a similar sized bolt, that could be it?

 

[coopec]

2BA has an outside dia of .185''

TPI of over 30tpi. So if it looks pretty fine, next to a similar sized bolt, that could be it?

Could we have that in English please?

TPI = Threads per inch. Yes the threads on the bolt are quite fine.
2BA = ???
Outside diameter is .190 (but I suppose .005" is not much - I'll check again.)