Date: 10 January 2020. Shaft and
Sometimes having just the right
part can be the difference between a minor inconvenience and a major
hassle. One such item that I keep aboard Seaweed are spare
keys. No, not the kind of keys that go into a lock. These are made
of square stainless steel
bar stock. Having a couple of spares aboard your boat is a Good
STOCK ↓ made of 303 Stainless.
The bar stock is used to make keys. Keys connect the
shaft to both your transmission and the propeller. They are
necessary to your propulsion system.
This is an item you will need at some
point, especially if your boat is 20-plus years old. Get the proper
size for your vessel. Seaweed has a 1.25" shaft. My bar stock is
5/16" solid square stainless steel. Each bar aka "key" is cut to
A couple vessels away from me
the fellow has the same 1.25" diameter shaft. His key for the
propeller is 5/16" like mine. The key his boat requires is just 3" long.
Knowing the proper length is important too.
This is the
that connects my shaft to the transmission:
You can measure the width of the key at the
shaft/coupler connection. If I did not
know the correct length I would buy a one foot piece then cut my own
Frankly I'm not an
expert on what your boat will require. Empirically (with just my
boat and one other as a sample) for a 1.25" shaft the bar stock required is
5/16". This is something you need to verify for your vessel.
I chose to purchase from from the
Midwest Steel and Aluminum company. There is no affiliate, no
bonus back to me, etc. This is the place I found online back in 2016
and is still in business. I remember being particularly pleased with
It is important to buy something
strong that will
not rust. I chose to purchase stainless steel bar stock.
Midwest Steel [http://midweststeelsupply.com] cut the bar stock the exact
length I needed to fit my Seaweed. I don't recall if there was an
added fee for said service.
I labeled my spares with the
details necessary to remember in years to come.
I have spares and know where I bought them. The
written details make sharing said information with fellow boaters
Every older boat
should have at least two extra bar stock keys in the stash of spares
aboard. Though not a first line purchase by any means, this item
might just save the day. Finding stainless steel bar stock in a
small town is nearly impossible.
I have sheared both the propeller key
AND a few years later the key that connects the transmission coupler
to the shaft. Seaweed was 30-ish years old at the time. Both I
suspect were originals from when she was built in 1983. I say that because those keys were bronze.
That is life
afloat. Seaweed is almost a Supply Ship by virtue of my having lived
aboard her so many years. Like most, as things break I replace and
purchase a spare. Most of us in it for the long term do the same.
Thank you for reading. Happy
Addendum: A follow-up
article with more details about shaft keys has been posted. It
is located here:
How Shaft Keys Work
Do you have spare bar stock aboard your vessel?
And, have you any opinion of stainless steel versus bronze or monel? I
have a stainless shaft.
Regarding the Comments Section,
found at the end of every article:
Before you type in each block be
sure to hit the backspace key. Coding inserts a space in every box.
Your email address will come back as malformed unless you remove
that space. (You don't have to include your email address.)
The capcha is case sensitive.
In the Bilges,
Removing Blood Stains ~
Previous Post ...
... Next Post
Nifty Nantucket Bagg
(plus Harbor Freight tool rule)