[25] This iron comes in sheets 28 × 56 inches = 10.88 square feet of area.

Russia
gauge
number.		 Birmingham
wire-gauge
number.		 Thickness
in decimal
parts of
an inch.
7 29   .013
8 28   .014
9 27   .016
10 26   .018
11 25   .020
12 24 1⁄2 .021
13 24   .022
14 23 1⁄4 ——
15 22 3⁄8 ——
16 21 1⁄2 ——

The following table gives the gauge numbers to which galvanized iron is made.[26]

[26] Galvanized iron is made to the Birmingham wire-gauge, the thickness includes the galvanizing, the sheets being rolled thinner to allow for it.

Gauge
number.		 Thickness. Gauge
number.		 Thickness.
  Inch.   Inch.
14 .083 23 .025
16 .065 24 .022
17 .058 25 .02
18 .049 26 .018
19 .042 27 .016
20 .035 28 .014
21 .032 29 .013
22 .028    

In the following table is given the American gauge sizes and their respective thicknesses for sheet zinc.

Gauge and Thickness. Gauge and Thickness.
Number. Approximate
Birmingham
wire-gauge.		 Thickness in
fractions of
an inch.		 Number. Approximate
Birmingham
wire-gauge.		 Thickness in
fractions of
an inch.
1 —— 0.0039 16 —— 0.0447
5 —— 0.0113 17 —— 0.0521
6 —— 0.0132 18 —— 0.0596
7 —— 0.0150 19 —— 0.0670
8 28 0.0169 20 —— 0.0744
9 27 0.0187 21 —— 0.0818
10 26 0.0224 22 —— 0.0892
11 25 0.0261 23 —— 0.0966
12 24 0.0298 24 —— 0.1040
13 —— 0.0336 25 —— 0.1114
14 —— 0.0373 26 —— 0.1189
15 —— 0.0410      

The Belgian sheet zinc gauge is as follows:

Gauge
number.		 Thickness in
decimal parts
of an inch.		 Gauge
number.		 Thickness in
decimal parts
of an inch.
1 .004 14 .037
2 .006 15 .041
3 .008 16 .045
4 .009 17 .052
5 .011 18 .059
6 .013 19 .067
7 .015 20 .074
8 .017 21 .082
9 .019 22 .089
10 .022 23 .097
11 .026 24 .104
12 .030 25 .111
13 .034 26 .120

The gauge sizes of the bores of rifles are given in the following table,[27] in which the first column gives the proper gauge diameter of bore, and the second the actual diameter containing the errors found to exist from errors of workmanship. The standard diameters are supposed to be based upon the number of spherical bullets to the pound weight, if of the same diameter as the respective gauge sizes.

[27] From The English Mechanic.

No. of
Gauge.		 Diameter of Bore. No. of
Gauge.		 Diameter of Bore.
4  varies from  1.052  to  1.000 14  varies from  .693  to  .680
6 „ .919 „ .900 16 „ .662 „ .650
8 „ .835 „ .820 20 „ .615 „ .610
10 „ .775 „ .760 24 „ .579 „ .577
12 „ .729 „ .750 28 „ .550 „ .548

The following table gives the result of some recent experiments made by Mr. David Kirkaldy, of London, to ascertain the tensile strength and resistance to torsion of wire made of various materials:

Kind of wire tested. Pulling stress per sq. in.
Unannealed. Annealed.
  Pounds. Pounds.
Copper 63,122 37,002
Brass 81,156 51,550
Charcoal iron 65,834 46,160
Coke iron 64,321 61,294
Steel 120,976 74,637
Phosphor bronze,  No. 1 159,515 58,853
„ No. 2 151,119 64,569
„ No. 3 139,141 54,111
„ No. 4 120,900 53,381
Kind of wire tested. Ultimate
extension in
per cent.
Annealed.		 No. of twists in
5 inches.
Unannealed. Annealed.
Copper 34 .1 86 .8 96
Brass 36 .5 14 .7 57
Charcoal iron 28   48   87
Coke iron 17   26   44
Steel 10 .9 [28] 79
Phosphor bronze,  No. 1 46 .6 13 .3 66
„ No. 2 42 .8 15 .8 60
„ No. 3 44 .9 17 .3 53
„ No. 4 42 .4 13   124

[28] Of the eight pieces of steel tested, three stood from forty to forty-five twists, and five stood one and a half to four twists.

The following, on some experiments upon the elasticity of wires, is from the report of a committee read before the British Association at Sheffield, England.

“The most important of these experiments form a series that have been made on the elastic properties of very soft iron wire. The wire used was drawn for the purpose, and is extremely soft and very uniform. It is about No. 20 B.W.G., and its breaking weight, tested in the ordinary way, is about 45 lbs. This wire has been hung up in lengths of about 20 ft., and broken by weights applied, the breaking being performed more or less slowly.

“In the first place some experiments have been tried as to the smallest weight which, applied very cautiously and with precautions against letting the weight run down with sensible velocity, will break the wire. These experiments have not yet been very satisfactorily carried out, but it is intended to complete them.

“The other experiments have been carried out in the following way: It was found that a weight of 28 lbs. does not give permanent elongation to the wire taken as it was supplied by the wire drawer. Each length of the wire, therefore, as soon as it was hung up for experiment, was weighted with 28 lbs., and this weight was left hanging on the wire for 24 hours. Weights were then added till the wire broke, measurements as to elongation being taken at the same time. A large number of wires were broken with equal additions of weight, a pound at a time, at intervals of from three to five minutes—care being taken in all cases, however, not to add fresh weight if the wire could be seen to be running down under the effect of the weight last added. Some were broken with weights added at the rate of 1 lb. per day, some with 3⁄4 lb. per day, and some with 1⁄2 lb. per day. One experiment was commenced in which it was intended to break the wire at a very much slower rate than any of these. It was carried on for some months, but the wire unfortunately rusted, and broke at a place which was seen to be very much eaten away by rust, and with a very low breaking weight. A fresh wire has been suspended, and is now being tested. It has been painted with oil, and has now been under experiment for several months.

“The following tables will show the general results of these experiments. It will be seen, in the first place, that the prolonged application of stress has a very remarkable effect in increasing the strength of soft iron wire. Comparing the breaking weights for the wire quickly broken with those for the same wire slowly broken, it will be seen that in the latter case the strength of the wire is from two to ten per cent. higher than in the former, and is on the average about five or six per cent. higher. The result as to elongation is even more remarkable, and was certainly more unexpected. It will be seen from the tables that, in the case of the wire quickly drawn out, the elongation is on the average more than three times as great as in the case of the wire drawn out slowly. There are two wires for which the breaking weights and elongations are given in the tables, both of them ‘bright’ wires, which showed this difference very remarkably. They broke without showing any special peculiarity as to breaking weight, and without known difference as to treatment, except in the time during which the application of the breaking weight was made. One of them broke with 441⁄4 lbs., the experiment lasting one hour and a half; the other with 47 lbs., the time occupied in applying the weight being 39 days. The former was drawn out by 28.5 per cent. on its original length, the latter by only 4.79 per cent.

“It is found during the breaking of these wires that the wire becomes alternately more yielding and less yielding to stress applied. Thus from weights applied gradually between 28 lbs. and 31 lbs. or 32 lbs., there is very little yielding, and very little elongation of the wire. For equal additions of weight between 33 lbs. and about 37 lbs. the elongation is very great. After 37 lbs. have been put on, the wire seems to get stiff again, till a weight of about 40 lbs. has been applied. Then there is a rapid running down till 45 lbs. has been reached. The wire then becomes stiff again, and often remains so till it breaks. It is evident that this subject requires careful investigation.”

TABLES SHOWING THE BREAKING OF
SOFT IRON WIRES AT DIFFERENT SPEEDS.

I.—Wire Quickly Broken.
Rate of adding weight. Breaking
weight in
pounds.		 Per cent. of
elongation on
original
length.
Dark Wire.[29]    
01⁄4  lb. per  minute 45   25 .4
1 „ 5  minutes 45 1⁄4 25 .9
  „ 5 „ 45 1⁄4 24 .9
  „ 4 „ 44 1⁄4 24 .58
  „ 3 „ 44 1⁄4 24 .88
  „ 3 „ 45 1⁄4 29 .58
  „ 5 „ 44 1⁄4 27 .78
Bright Wire.[29]    
1  lb. per  5  minutes 44 1⁄4 28 .5
  „ 5 „ 44 1⁄4 27 .0
  „ 4 „ 44 1⁄4 27 .1

[29] The wire used was all of the same quality and gauge, but the “dark” and “bright” wire had gone through slightly different processes for the purpose of annealing.

II.—Wire Slowly Broken.
Weight added and
number of
experiment.		 Breaking
weight in
pounds.		 Per cent. of
elongation on
original length.
1.  1  lb. per  day 48   7.58    
2.   „ „ 46   8.13    
3.   „ „ 47   7.05    
4.   „ „ 47   6.51    
5.   „ „ 47   8.62    
6.   „ „ 47   5.17    
7.   „ „ 46   5.50    
8.   „ „ 47   6.92    bright wire
1.  3⁄4  lb. per  day 49   8.50    
2.   „ „ 48 1⁄4 8.81    
3.   „ „ Broken by accident.
4.   „ „ 46   7.55    
5.   „ „ 46   6.41    
6.   „ „ 45 1⁄2 6.62    
1.  1⁄2  lb. per  day 48   8.26    
2.   „ „ 50   8.42    
3.   „ „ 49   7.18    
4.   „ „ 47   4.79 }  bright wires
5.   „ „ 46 1⁄2 6.00

The American Standard diameters of solid drawn or seamless brass and copper tube are as in the following table.

Outside
diameter.		 Thickness
Stubs’s
wire-gauge.		 Weight per
running foot.
Brass tubes.		 Weight per
running foot.
Copper tubes.
  5⁄8 18   3⁄8   3⁄8
  3⁄4 17   1⁄2   1⁄2
  13⁄16 17   9⁄16   9⁄16
  7⁄8 17   5⁄8   5⁄8
  15⁄16 16   11⁄16   11⁄16
1   16   3⁄4   3⁄4
1 1⁄8 16   7⁄8   7⁄8
1 1⁄4 12  and  14 1 1⁄4 1 1⁄4
1 3⁄8 12 „ 14 1 3⁄8 1 3⁄8
1 1⁄2 12 „ 14 1 1⁄2 1 6⁄10
1 5⁄8 12 „ 14 1 5⁄8 1 7⁄10
1 3⁄4 12 „ 14 1 3⁄4 1 8⁄10
1 13⁄16 12 „ 14 1 13⁄16 1 9⁄10
1 7⁄8 12 „ 14 1 7⁄8 1 15⁄16
1 15⁄16 12 „ 14 2   2 1⁄10
2   12 „ 14 2 1⁄8 2 1⁄4
2 1⁄8 12 „ 14 2 1⁄4 2 3⁄8
2 1⁄4 12 „ 14 2 3⁄8 2 1⁄3
2 3⁄8 12 „ 14 2 1⁄2 2 2⁄3
2 1⁄2 11 „ 13 2 3⁄4 3  
2 5⁄8 11 „ 13 3   3 1⁄8
2 3⁄4 11 „ 13 3 1⁄8 3 1⁄4
2 7⁄8 11 „ 13 3 1⁄4 3 3⁄8
3   11 „ 13 3 3⁄8 3 1⁄2
3 1⁄8 11 „ 13 3 1⁄2 3 3⁄4
3 1⁄4 11 „ 13 3 7⁄8 4 1⁄8
3 3⁄8 11 „ 13 4 1⁄8 4 1⁄4
3 1⁄2 11 „ 13 4 1⁄4 4 3⁄8
4   11 „ 13 5   5 1⁄4
4 1⁄4 11 „ 13 6   6 1⁄2
5   10 „ 12 7   8  
6   10 „ 12 9   10  

Chapter XVI.—SHAPING AND PLANING MACHINES.

The office of the shaping machine is to dress or cut to shape such surfaces as can be most conveniently cut by a tool moving across the work in a straight line.

The positions occupied among machine tools at the present time by shaping and planing machines are not as important as was the case a few years ago, because of the advent of the milling machine, which requires less skill to operate, and produces superior work.

All the cutting tools used upon shaping and planing machines have already been described with reference to outside tools for lathe work, and it may be remarked that a great deal of the chucking done on the shaping and planing machine corresponds to face plate chucking in the lathe. Both shaping machines and small planing machines, however, are provided with special chucks and work-holding appliances that are not used in lathe work, and these will be treated of presently. On large planing machines chucks are rarely used, on account of the work being too large to be held in a chuck. Shaping machines are also known as shapers and planing machines as planers.

Fig. 1496

Fig. 1496.

The simplest form of shaping machine, or shaper as it is usually termed in the United States, is that in which a tool-carrying slide is reciprocated across the work, the latter moving at the end of each back stroke so that on the next stroke the tool may be fed to its cut on the work. Fig. 1496 represents a shaper of this kind constructed by Messrs. Hewes and Phillips, of Newark, New Jersey, in which p is a cone pulley receiving motion from a countershaft, and driving a pinion which revolves the gear-wheel q, whose shaft has journal bearing in the frame of the machine. This shaft drives a bevel pinion gearing with a bevel-wheel in one piece with the eccentric spur-wheel s, which is upon a shaft having at its lower end the bevel-wheel b to operate the work-feeding mechanism. s drives an eccentric gear wheel r, fast upon the upper face of which is a projection e, in which is a T-shaped groove to receive and secure a wrist or crank pin which drives a connecting rod secured to the slide a by means of a bolt passing through a, and secured to the same by a nut d.

When the gear-wheel r revolves, the connecting rod causes slide a to traverse to and fro endways in a guideway, provided on the top of the frame at x. On the end of this slide is a head carrying a cutting tool t, which, therefore, moves across the work, the latter being held in the vise v, which is fast upon a table w upon a carriage saddle or slider p, which is upon a horizontal slide that in turn fits to a slide vertical upon the front of the machine, and may be raised or lowered thereon by means of an elevating screw driven by a pair of mitre-wheels at f. The slider and table w (and therefore the vise and the work) are moved along the horizontal slide to feed the work to the tool cut as follows. A short horizontal shaft (driven by the bevel pinions at b), drives at its outer end a piece c, having a slot to receive a crank pin driving the feed rod n, which operates a pawl k engaging a ratchet wheel which is fast upon the horizontal screw that operates slider p.