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4,438 Posts
Discussion Starter · #1 ·
Bought this SS Bolt To Replace the Un-Predictable Sliding Pin on my Trolling Motor After install I Noticed I needed a couple of extra washers No Big Deal ... So i go ahead and secure it

Well forward fast to today Tried to Remove the Nut and Holy Crap ! Seized Tighter than a drum !
Tried a couple of Turns sprayed a little Blaster and waited ... NO Good !

Grinding Is NOT an option as heat would Ruin the Housing !!! So I was lucky enough to Wring it off !

The Bolt was Installed only a week ago !

This bolt came from a Famous Hardware Chain (Supposedly Grade 5 Us Made) I will attempt an exchange tomorrow ...

Gawd now I have to use Bronze Nuts ??? Just remember It takes about $250.00 worth of Bolts and Various Fasteners to rig a 13 foot Gheenoe !


I Love!
2,820 Posts
every once in a while i'll get them like that too where they'll skip a thread or so and it's all down hill from there :mad:

Paddling away...
6,588 Posts
Extremely common.
Happened all the time at work.
Once tightened down with a lock nut, the bolt will snap like shown above.
And sometimes the nuts mount crooked and then the bolt has to be broken off.
Can be frustrating at times.

Stainless only means "Stain Less"

The more nickle content, the less rust or "stain".  Less nickle (higher grade) the more it will rust or "stain"

Typically the higher nickel content is what is found in chains due to cost and the perception that SS should not rust.  It unfortunately is also a softer material so if assembled rapidly (generating heat) it will seize.  Also over tightening will distort the threads with the same effect.

You pic shows the use of nylock's an my preference.  However they seem to be the worst for generating heat during assembly.  If your using a screw gun, feather the trigger so the screw turns very slow, as slow as if you were turning a screwdriver by hand.  You can also dab just a bit of lube (grease) on the tip of the threads when you start.  If you generate heat (warm to the touch), back it off , throw it away and start over. With practice your waste will be minimized but you will probably always have a percentage of failures.

While "coarse thread" is normally readily available, if you have a situation were you need to really torque your fasteners, you should find "fine thread" is more tolerant. ;)

When seized like the one shown here, anything 1/4" or under is easier to just wring off in reverse.

Reusing SS fasteners increases the potential of seizing but like previously stated, sometimes, you'll just get a dud.

Hope this helps.

You might also find this helpful. Look at the head of the bolt. I doubt it's a "Grade 5" ;)

Stainless Steel
Stainless steel is an alloy of low carbon steel and chromium for enhanced corrosion characteristics. Stainless steel is highly corrosion resistant for the price and because the anti-corrosive properties are inherent to the metal, it will not lose this resistance if scratched during installation or use.

It is a common misconception that stainless steel is stronger than regular steel. In fact, due to the low carbon content, stainless steel cannot be hardened. Therefore when compared with regular steel it is slightly stronger than an un-hardened (grade 2) steel fastener but significantly weaker than hardened steel fasteners.

Stainless steel is also much less magnetic than regular steel fasteners though some grades will be slightly magnetic.

18-8 Stainless
18-8 refers to any stainless steel containing approximately 18% chromium and 8% nickel. This is the most common stainless designation for hardware. For information on 18-8 stainless steel material properties see our Material Grade Identification and Properties Chart.

Steel is the most common fastener material. Steel fasteners are available plain as well as with various surface treatments such as zinc plating, galvanization, and chrome plating.

Steel fasteners are commonly available in 4 grades. Many other grades exist but are used far less often. The most common grades are Grade 2, Grade 5, Grade 8, and Alloy Steel. Grade 2, 5, and 8 are usually plated with a silver or yellow zinc coating or galvanized to resist corrosion.

Determining Bolt Grade
Bolts of different grades are marked on the head to show what grade bolt they are. For a list of the most common grade markings see our Material Grade Identification and Properties Chart.

Grade 2
Grade 2 is a standard hardware grade steel. This is the most common grade of steel fastener and is the least expensive. Grade 2 bolts have no head marking (sometimes a manufacturer mark is present).

Grade 5
Grade 5 bolts are hardened to increase strength and are the most common bolts found in automotive applications. Grade 5 bolts have 3 evenly spaced radial lines on the head.

Grade 8
Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions. Grade 8 bolts have 6 evenly spaced radial lines on the head.

Alloy Steel
Alloy steel bolts are made from a high strength steel alloy and are further heat treated. Alloy steel bolts are typically not plated resulting in a dull black finish. Alloy steel bolts are extremely strong but very brittle.

Silicon Bronze
Silicon bronze, often referred to simply as bronze, is an alloy made mostly of copper and tin with a small amount of silicon. Bronze is used primarily in marine environments. It is preferred over stainless in wooden boat construction and re-fastening due to its superior corrosion resistance, and over brass due to its higher strength. Bronze is similar to copper in color and is also sometimes seen in fine woodworking where it is used for its appearance. The main drawback of bronze is its high cost.

Brass is an alloy of primarily copper and zinc. Brass is highly corrosion resistant and electrically conductive. However, its use as a fastener is somewhat limited due to its relative softness. It is used primarily for its appearance.

5,732 Posts
Here's a tip I learned some years ago.... When I'm buying stainless I bring a small magnet with me. You'll find a wide variation in the magnetic properties of the stainless sold everywhere. If you want the stuff to be fairly rust free avoid pieces that the magnet likes....

Other than that, SS hardware has some significant downsides as mentioned above. One other minor point, if you have to drill into stainless, go as slow as your drill will turn and be patient. I ruined a few drill bits before someone was kind enough to show me the right way to do it...

786 Posts
It "gall" or seize. There is an easy fix. Just use "anti-seize" compound on all stainless steel grades and you will likely be okay.

Stainless is soft, but tough. I use it for everything associated with boats. (not engines) You can increase the fastener size if unsure of strength requirements.

Best regards,

4,438 Posts
Discussion Starter · #9 ·
Ron You were right I was not thinking when I mentioned "Grade 5" My aircraft maintenance Instructor would have me drawn and Quartered for that remark !!!

This is what I use I checked the heads of the bolts ... Unless the Chinese are Counterfeiting Bolts AGAIN !!!

Nut went on easy But bound upon removal (all by Hand ) I checked the winch roller Bolt NO problem

Got my exchange No problem ... Thanks to ALL ! Good stuff :)

Significance and Use

For the purposes of determining compliance with the specified limits for properties listed in this specification, an observed value or calculated value shall be rounded in accordance with Practice E 29.

1. Scope

1.1 This specification covers the requirements for stainless steel bolts, hex cap screws, and studs 0.25 to 1.50 in., inclusive, in nominal diameter in a number of alloys in common use and intended for service applications requiring general corrosion resistance.

1.2 Seven groups of stainless steel alloys are covered, including twelve austenitic, two ferritic, four martensitic, and one precipitation hardening.


1 304, 305, 384, 304 L, (CW) cold workedC
18-9LW, 302HQD 
2 316, 316 L (CW) cold workedC
3 321, 347 (CW) cold workedC
4 430E (CW) cold workedC
5 410F (H) hardened and tempered
6 431 (H) hardened and tempered
7 630 (AH) age hardened 

A Unless otherwise specified on the inquiry and order, the choice of an alloy from within a group shall be at the discretion of the fastener manufacturer (see 6.1).

B See 4.2 for options.

C Sizes 0.75 in. and larger may be hot worked and solution annealed.

D When approved by the purchaser, Alloys 303, 303Se, or XM1 may be furnished.

E When approved by the purchaser, Alloy 430F may be furnished.

F When approved by the purchaser, Alloys 416 or 416Se may be furnished.

1.3 Supplementary requirements of an optional nature are provided, applicable only when agreed upon between the manufacturer and the purchaser at the time of the inquiry and order.

1.4 Suitable nuts for use with bolts, hex cap screws, and studs included in this specification are covered by Specification F 594. Unless otherwise specified, all nuts used on these fasteners shall conform to the requirements of Specification F 594, shall be of the same alloy group, and shall have a specified minimum proof stress equal to or greater than the specified minimum full-size tensile strength of the externally threaded fastener.

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

ASTM Standards
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A276 Specification for Stainless Steel Bars and Shapes
A342/A342M Test Methods for Permeability of Feebly Magnetic Materials
A380 Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems
A484/A484M Specification for General Requirements for Stainless Steel Bars, Billets, and Forgings
A493 Specification for Stainless Steel Wire and Wire Rods for Cold Heading and Cold Forging
A555/A555M Specification for General Requirements for Stainless Steel Wire and Wire Rods
A564/A564M Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes
A582/A582M Specification for Free-Machining Stainless Steel Bars
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A967 Specification for Chemical Passivation Treatments for Stainless Steel Parts
D3951 Practice for Commercial Packaging
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E594 Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid Chromatography
F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
ASME Standards
B18.2.1 Square and Hex Bolts and Screws, Including Hex Cap Screws


Index Terms

bolts; general use; hex cap screws; stainless; studs, Stainless steel screws--specifications; Steel bolting materials--specifications; Studs (materials/applications)--specifications; Bolting materials; Corrosive service applications; Hex cap screws/studs; Stainless steel bolting materials--specifications; ICS Number Code 21.060.10 (Bolts, screws, studs)

DOI: 10.1520/F0593-02R08

ASTM International is a member of CrossRef.


ASTM F593 (Fastener Standards)
Citing ASTM Standards
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