#1
IP: 70.177.229.241
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Prop/Coupling bolts...
Who's got the specs on the bolts? Can't find the originals, looking to replace. Graded bolts okay to use? Thanks,
- JM
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#2
IP: 173.166.26.241
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3/8" - 24 (NF) x 1 1/4" long should do it.
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#3
IP: 24.152.131.220
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Well done Hanley. There are few people who know how to properly name a machine screw these days. It's such a rarity that those who do stand out from the crowd.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#4
IP: 70.177.229.241
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Excellent, thank you!
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#5
IP: 206.125.176.3
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H3 - I used stainless in mine...not sure exactly what the materials are (i.e. different metals down there and all) - I did notice a small bit of corrosion around the coupler from the stainless seizing wire when I disassembled mine, so there was some reaction going on there.
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#6
IP: 148.170.241.1
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I bought Grade 8 bolts from Lowe's for mine.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#7
IP: 70.177.229.241
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__________________
Blog @ http://www.youthstrikesback.com Pics @ http://www.flickr.com/photos/66632238@N02/sets/ Twitter @ http://twitter.com/captclownshoes Facebook @ http://www.facebook.com/youthstrikesback |
#8
IP: 174.94.27.60
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Quote:
There, fixed it for ya... |
#9
IP: 24.152.131.220
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Not to pick nits but UNF and 24 tpi for a 3/8" machine screw are redundant. We never used the terms coarse or fine to describe thread pitch.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#10
IP: 70.177.229.241
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You guys wanna translate all that for the laymen?
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#11
IP: 24.152.131.220
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The reference 67 made was for fine threads or coarse threads. UNF = Unified National Fine [thread], UNC = Unified National Coarse.
I'm sure there are several websites that describe it better but here's a remedial version: The machine screw (commonly and inaccurately referred to as 'bolt') Hanley mentioned was 3/8"-24 x 1 1/4" HHMS. 3/8" = diameter of the machine screw or the hole it fits in. -24 = the number of threads per inch (tpi, also known as thread pitch), fine threads in this case. Coarse threads for a 3/8" machine screw would be 16 tpi. Different diameter machine screws have their own common threads. 1/4- 20 is the coarse thread for 1/4" machine screws, 1/4 - 28 is fine thread. x 1 1/4" = the length of the machine screw from the gripping part of the head to the threaded end. HHMS = Hex Head Machine Screw. There's a wide variety of head shapes: Flat head = FH Oval head = OH Pan head = PH Round head = RH and so on ad infinitum. A recent project on my boat had me replacing the lower chainplate bolts. I picked up 3/8-16 x 1 3/4" RHMS in 18-8 SS (18-8 is the common alloy of stainless fasteners, SS = stainless steel). That designation told the supplier exactly what I needed in size, thread pitch, length, head style and material. A note on grading, steel machine screws can be had in a variety of strengths. This next statement may be inaccurate but as I remember, grade 3 is your garden variety common steel, grade 8 is serious strength. On the heads of graded hex head machine screws there are raised lines, the number and position of which identify its grade. How'd we do?
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 08-26-2011 at 12:16 AM. |
#12
IP: 70.177.229.241
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Quote:
Just kidding...excellent translation. You're right about the graded lines, also the colors too....5's are blue, 8's are gold. I don't know about 3's....Any time I've ever needed a graded "machine screw," I was always told to get 5 or 8.
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#13
IP: 174.94.27.60
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Quote:
Just saying! |
#14
IP: 148.170.241.1
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More than you ever would want to know about bolt/screw grading...
But for purposes of this discussion - This is the head of a Grade 5 bolt: This is a Grade 8: I have found both at Lowe's - and both were a gold-ish color. But as has been said above, I've also seen Grade 8 bolts that are just a plain steel color.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
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