The history and introduction of bolt
2008-08-18

  In today’s life we can see the bolt everywhere. For example, we usually use it to attach two things. Bolt is a metal rod that has a head on one end and threads on the other and is used to fasten together lumber. In fact, the bolt comes from America very long ago. So we come to know something about it.            Bolt comes in many variations throughout the history of the carriage era. In looking through the carriage collection of the Carriage Museum of America in storage we noticed the nuts on vehicles built in the early 1800s were proportionately flatter and squarer than those built later which had hampered corners on the nuts. On the earlier vehicles less care was taken to trim off the bolts flush with the nuts as the later vehicles often had the bolts trimmed off flush with the nuts with a little burr on the end of the bolt to keep the nut from coming off.            For further matters that are not visible and more factual information there is "The History of the Nut and Bolt Industry in America" by W.R. Wilbur in 1905. The first application of machinery for making bolts and screws was made by Besson in France in 1568, who afterwards contrived a screw-cutting gauge or plate to be used on lathes. In 1641, almost a century later, this device was further improved by Hindley of York, England, and for many years was in general use.           The notion of a nut and bolt manufactory in America originated with Mr. Micah Rugg, a small country blacksmith, in the town of Marion, Southington Township, Connecticut in 1818. In studying the best methods of making tools to manufacture implements, he invented and brought out two machines for making carriage bolts.  In the New York Coach-Maker's Magazine, March 1868, page 151 we find the following description: "His first operation was to cut up bars of square iron into suitable lengths to form the intended bolts, then heating one end of these pieces, he rounded them with die and swage which were inserted into the mortise of his anvil. The next operation was to head these pieces, and disdaining the old method of the heading-tool, he employed for that purpose an improved drop-die. The surplus metal which formed around the head of the bolt by the drop he trimmed off with a die in a hand-press. Then with a winch, which carried the necessary fixtures upon one end of a shaft to which it gave motion, the bolt being held in this fixture, the threads were cut between dies, which were hinged at one end and had a weight attached to the other to hold them together with sufficient power to enable the die to cut the thread."           "It was several years before power was applied to perform this operation, and when that was done a boy could accomplish more and with greater ease than half-a-dozen men could previously with the old fixtures. It was about this time that the turned head was introduced, and, if we are not mistaken, it was to circumvent the patented process of the drop. The bolt-heads were headed with an appropriate tool, and the edges or sides were beveled, about fifteen blows of the hammer generally performing the operation, and then they were inserted in the end of a revolving mandrel, held there by a screw, and a tool similar to the quadrangular deck-scraper employed to fashion this head like the one as formed with the drop, water flowing in a succession of drops upon the head during the process to prevent the friction destroying the turning-tool. These bolts were then packed in paper envelopes and sent to market."            Up to 1839 Mr. Rugg's books showed a total manufacture and sale of about 3,000 bolts. During this year he devoted his whole attention to machine bolts and nuts. The following year, 1840, he took in as partner Mr. Martin Barnes, constituting the firm of Rugg & Barnes, the first company to manufacture bolts and nuts in America. Six operatives were employed, with a daily production of 500 bolts, consuming less than 60 pounds of Stitt's best brand of refined English bar iron, purchased at $140 per ton in New Haven and hauled with ox teams to Marion, a distance of 18 miles. About 300 pounds of Lehigh lump coal was used, costing $12 per ton on the docks and also transported to the factory by teams of oxen. The monthly payroll amounted to $150, payable largely in due bills and store orders; there being no regular pay day, notice was required to get cash as part payment.          He secured a patent on the second machine for carriage bolts for trimming bolt heads, dated October 22, 1842. The machine was operated with a hollow punch, in which the bolt was placed and forced through a trimming die. This was the starting point that led to bolt turning. As with many new and progressive ideas it was looked upon with suspicion--carriage smiths pronounced the bolts good for nothing and manufactured from "pot metal,", made malleable by some mysterious and fraudulent "Yankee" process--and it took some good marketing and and hard work to sell this new idea of manufactured bolts and nuts. Once the idea of manufactured nuts and bolts caught on, this led to a period of ingenious efforts to achieve economy and rapidity in the production of bolts. Bolts made by machinery were forged from square iron, the head being left intact, and the remainder was rounded and threaded to the required length. For a number of years all bolt forging machinery was designed to form bolts from the square bar on this principle.          Then it develops to today. When we see the bolt now, we can find it having many kinds. They have different shapes and functions. Next we have a look at its types:

Hex bolt Standard bolt: A standard bolt has a hex head and a smooth shoulder area beyond the standard amount of threading. Shorter lengths are fully threaded.

Fully threaded bolt: Tap bolts are fully threaded hex head bolts. The most common materials used for hex bolts are stainless steel, carbon steel, or alloy steel.

Stainless steel bolts are an attractive choice because they don't need any special coating to avoid corrosion. Carbon steel bolts are, however, the most common type that you will find in the average hardware store. These are usually zinc plated in order to resist corrosion. The strength of carbon steel hex bolts typically hover around 55 skis.

Lag bolt Often called a lag screw. Hex lag bolts are for fastening in wood. Available in a variety of materials. Steel stainless, steel, Lag bolts, often referred to as lag screws, and are available in a variety of materials.

Eye bolt Wire eye bolts :(also referred to as bent or turned eye bolts) are used for light duty applications, and should not be used for angular loads.

Drop forged eye bolts: Forged eye bolts are significantly stronger than wire eyes and are available in larger sizes. These bolts should not be used for angular loads.

Drop forged machinery eye bolts: Machinery eyes are fully threaded. Machinery eye bolts without a shoulder should not be used for angular loads.

Drop forged eye bolts with a shoulder: Forged eye bolts are significantly stronger than wire eyes and are available in larger sizes. These bolts should not be used for angular loads.

Drop forged machinery eye bolts with shoulder: Machinery shoulder eyes are fully threaded. These are the only eye bolts rated for an angular load.

Wire eye lags: (also referred to as screw thread eye bolts, eye screws, or turned/bent eye lags) have a wood screw thread for use in wood or lag anchors. Like wire eye bolts, wire eye lags are intended for light duty applications and should not be used for angular loads.

Hanger bolts Hanger bolts have wood thread on one end and machine thread on the other end. These bolts are frequently found in furniture.

Carriage bolts A bolt mostly used in wood with a domed top and a square under the head. This pulls into the wood as the nut is tightened. Carriage bolts, also known as plow bolts, are mostly used in wood. They have a domed top and a square under the head. This square pulls into the wood as the nut is tightened. 

     Certainly if we concern about the materials, we can see the detail information above.

Soft steel- Poor to piss-poor performance from new and rust easily. They held equally poorly in straight-out testing and horizontal crack pulls primarily because it was impossible to hammer them in any harder before they started to collapse. Highest was 11kN when the eye broke and the lowest 2kN when a blade peg came out as we were loading the tester. This particular 5mm piton disgraced itself even further only managing an average of 3kN for three pulls in the best case scenario. The manufacturer decided to protect these from corrosion by galvanizing them, perhaps overlooking the fact that zinc is one of the metals used in bearings due to its lubricating properties. Of course the galvanizing is immediately destroyed by the rock anyway.

Hard Cast Steel-Not many if any on the market these days, though I tested some older ones. These were both ¼" Lost Arrow /King Pin designs, one from Cassin and the other unmarked but appeared identical. Both had good holding power, at least good enough to break, the eye of the Cassin letting go at 18kN and the other losing it´s eye completely at 22kN.

Chrome Molybdenum Steel- As good as it gets performance wise but can get stress cracks appearing spontaneously even after years of good service particularly in the bent sheet types. Generations of climbers have relied on Yvon Chouinards finest and a 5/16" Lost Arrow up to its eye in a horizontal granite crack certainly is a fine thing. It only came out when the rock under it started to break up and held over 31kN. In the direct pull tests it was doing well at 19kN when the crack failed totally and certainly would have been much better in if the rock had been stronger.

Stainless Steel- Good holding power near chrome-molybdenum. I tried a few designs of these, conventional AISI316 6mm blades holding 13kN straight out but tended to collapse on hammering in. The same design but from an especially hardened material held 17kN in this direction as we could hit it in further. These two were good performers in the horizontal, the soft one getting 24kN and it’s hard buddy 27kN. The two welded rod designs I tried were a complete contrast, the 6mm ones being poor with 8kN and 11kN in the two directions whereas the 8mm versions held 13kN and 29kN. My idea for an active piton proved not to be so active after they were given a good beating, the results being almost identical with the normal versions at 14kN and 28kN. One advantage of stainless steel (as well with titanium) is its liability to galling, when the pressure is high enought the metal starts to seize onto the rock and removal becomes a question of tearing the material, this was easy to see on the hard rock tests and partially explains the good results Stainless pitons could suffer from stress corrosion cracking near the sea though with the right alloy this can be eliminated, at a price.

Titanium- Depending on the alloy used performance similar to soft steel or up to the level of stainless steel. We only had a few knife blades to test, acquired on some expedition by Karsten decades ago, and before you ask, they are not from USHBA. These proved to be astoundingly hard and one can only wonder from which part of the Russian space program the material came from.

In a word, they do have their advantages whether which material they are made of. You can choose it according your demand. Wish you good luck!