How to choose the right cutter P1 and P3 based on appearance?

Let's consider the key points that you need to pay attention to when choosing a gas cutter for comfortable work.

When choosing gas cutters, you need to decide what thickness of metal you plan to work with:

• Metal thickness up to 100 mm
• Metal thickness from 100 mm to 300 mm

Next, you need to understand what flammable gas you plan to use - acetylene, propane-butane.

Also, pay attention to the design features of the cutters. There are injection, universal 3-pipe cutters, on which you can use replaceable gas mixing mouthpieces for the required type of combustible gas, and kerosene cutters.

Injection cutters have long been known, are familiar to many specialists and are quite widespread. They are distinguished by their simplicity of design - but it must be remembered that due to technological features, such cutters should only be used with a fire-preventing valve installed.

Principle of operation

Metal cutting occurs due to its melting under the influence of a directed stream of oxygen on the line of the intended cut. After melting, the same jet blows out the oxides formed in the cut zone.

The use of gas cutters is effective in the following cases:

• If it is necessary to cut metal structures before subsequent melting during the sorting process.
• To correct defects formed during welding work.
• To eliminate the consequences of accidents.
• In foundry production to correct external defects on finished ingots.
• In metallurgy for cutting metal sheets and rolled products before installing metal structures.
• If necessary, preparation work before welding.
• When dismantling steel structures.

BULROS 450 VSPLUS

This model is suitable for heavy use and can cut up to 450 sheets of 70 g/m2 paper at a time. The model is made of durable materials and is equipped with a reciprocating cutter. The cutter is equipped with a special electric drive for pressing and cutting, which provides the model with precision paper cutting. The cutter is controlled using a digital control method, as well as a protection system.

Pros:

1. There are many cut protection systems;
2. Accuracy of paper cutting;
3. Digital control;
4. Disc brake;
5. Additional cabinet included.

Minuses:

1. Heavy weight;
2. Large dimensions.

Construction of gas cutters

The cutting torch consists of the following parts:

• Trunk.
• Tip.
• Handles equipped with nipples for connecting gas and oxygen hoses.
• Housings with valves designed to regulate the supply of gas and oxygen.
• Injector.
• Mixing chamber.
• A tube designed to supply oxygen and a combustible mixture.
• A connecting nut that serves to secure the barrel to the body of the device.

During operation of the device, gas is directed through hoses into the product body through nipples. In this case, the combustible gas must flow in a single-flow mode towards the western valve, and the oxygen must diverge into two streams, one of which is directed to the heating valve, and the second to the cutting oxygen valve located outside the handle.

When the oxygen preheating valve is open, gas under pressure is directed into the main injection hole. Discharged flammable gas is supplied to it through a series of peripheral holes.

Once the gases are mixed, they are directed to the mouthpieces through the lower tube of the handpiece.

IMPORTANT! When working with gas equipment, it is strictly prohibited:

• blow oxygen through the propane hose;
• change sleeves with each other.

Oxygen and heating gas are supplied to the tip head, which is removed from the annular gap. After the flame appears, the jet is directed to the site of the intended cut, after which the gas jet burns the metal and removes the by-product in the form of oxide.

To make cutting, the head of the device with the cutting jet is held at a certain distance from the workpiece, after which a narrow slot remains in the processed area, limited by the lateral and frontal planes.

The maximum flame temperature produced by gas cutters running on propane is 2800 degrees. For devices running on acetylene fuel, this figure is 3100 degrees.

Instructions for use

The preparatory stage consists of inspecting the equipment.
Check that the hoses are connected correctly, that the fasteners are tightened, and that they are tight. It is recommended to lubricate the valve seals with glycerin and then begin work. Cutting steps:

• open the valve with oxygen, then with flammable gas;
• set fire (with a match, lighter) to the resulting mixture;
• regulate the jet using valves to the desired size and flow rate;
• warm up the cutting area;
• open the cutting oxygen valve and perform the operation;
• close the valve with flammable gas, then with oxygen;
• If necessary, cool the tip in cold water.

Open the valves on the cylinders

Open the valves on the cutter

Set the mixture on fire

It is important to remember about PPE - gloves, covered hands, gas cutting glasses, etc. It is advisable to have comfortable shoes, non-synthetic clothing, and completely degrease the cut area, otherwise an explosion when oxygen comes into contact with oil is inevitable. It is not worth reminding that smoking near cylinders is prohibited.

Types of gas cutters

Gas cutting equipment is traditionally qualified according to various criteria, but the main ones include the type of combustible material used and the characteristics of mixing gas with oxygen. Also, cutters can be divided according to purpose (specialized and universal), as well as the type of cut produced (separation, surface and oxygen-flux).

Injection

Injection-type devices operate on the principle of intra-nozzle mixing of working gases. This design allows for high reliability and safety of the mechanisms. This is due to the fact that flammable gas and oxygen are supplied to the nozzle through separate channels and mixed in a special mixing chamber immediately before supply.

Injectorless

Injectorless cutters do not have a special chamber for mixing gases. Oxygen is supplied to the nozzle through two channels, flammable gas through a third. The substances are mixed only inside the cutter head. Devices of this type require higher gas pressure to operate effectively compared to injection devices.

Roller cutter (trimmer or disc)

It is a metal or plastic base on which markings of different formats and a ruler are applied for ease of cutting. On one side of the cutter there is a transparent strip with a recess along which a roller knife mounted in a cassette or handle moves. Paper is inserted under the transparent bar, then a cassette with a roller cutter presses the paper and cuts it. The roller blade can move in both directions from left to right and vice versa. The cutting line is visible through the transparent strip.

Pros of roller cutters:

• Almost all models have a visible cutting line
• has a self-sharpening knife or replaceable blades that are purchased separately
• You can cut paper from 0.5 mm

Disadvantages of roller cutters:

• After a year of use, the cutter may shift the paper and cut unevenly, the error is 0.5-2 mm.

I have a Hama ProCut 460 cutter (made in Germany). I've been using it for about 10 years. The working surface measures 46x15 cm (18 inches), the cutter itself measures 56x20.5 cm. Made of durable plastic. The knife is self-sharpening; when cutting, the blade is pressed tightly against the counter-blade and sharpens it during the cutting process. A transparent plastic bar presses the paper as the knife moves. Cuts paper with a density of up to 300 g/m2. Standard paper sizes are applied to the working surface, there is a ruler in centimeters and inches, lines with degrees 45, 30, 15. The manufacturer states that it cuts 5 sheets of paper with a density of 80g/m2 in 1 pass. In fact, a cutter that has been used for a year or more takes no more than 3 sheets, and a new one takes 4 sheets maximum.

After 3 years of use, when cutting thick paper 300 g/m2, the knife began to jump off the transparent bar; you have to push it back in. After two years, the cutter began to shift the paper by 0.5-1mm. I found a way out - first I put lines on both sides where I need to cut, and then I put it in the middle of the work surface, adjust it along the lines and cut. It turns out smooth. Also, the transparent strip has become loose over 10 years, but this does not interfere with cutting, the cutter presses the paper tightly at the moment of cutting.

Now let's talk about commonly seen roller cutters.

The ProCision paper cutter from Fiskars is designed for cutting dense materials such as chipboard, beer and bookboard, plywood, it also cuts paper and the thickest designer cardboard. Thanks to the double rail system, it cuts paper more accurately and does not allow the blade to “walk”. The blade of the cutter is self-sharpening and does not need to be replaced. Cutting depth 3 mm. It has centimeter and inch markings and is protected from abrasion. Conveniently folds for storage. There is a paper clamp. The cutter itself is heavy.

Trimmer cutter

They come with a straight cut, with replaceable curved blades and a creasing line. Let's take a closer look at cutters from the most famous brands - We R Memory Keepers, American Crafts and Fiskars.

Twist Trimmer Magnetic Combo Pack 16 from We R Memory Keepers . This cutter has 8 disc blades - straight, ripped edge, wave, postage stamp, zig zag, comb, punch and crease line. An attachment with a blade is placed on the magnetic ruler, the ruler is placed on the mat, paper is placed under the ruler and cut. The length of the ruler is 39 cm, has divisions in inches and centimeters. Attachments are sold separately.

Trim and Score Board from We R Memory Keepers 2 in 1 cutter and scoring board. Available in two colors: black with mint and white with mint. The set includes a spare blade, an envelope ruler and a creasing stick.

Pros of the cutter:

• It has a large working surface of 30x30 cm and folds compactly in half
• The ruler is located on both sides with one in inches and the other in centimeters
• Cuts paper up to 250 g thick

Cons of the cutter:

• On the side of the centimeter ruler there is a place to store the creasing stick and because of this part of the centimeter ruler is cut off
• When cutting from bottom to top, the paper gets a little dirty
• Sometimes it cuts unevenly, shifting the paper to the side by 0.5-1 mm

The Portable Cartridge cutter from American Crafts has three replaceable cartridges - straight line, comb and creasing line, the rest of the knives can be purchased in addition. A total of 7 designs were released. There are 6 trays for storing knives on the cutter.

The size of the cutting surface is 20x30.5 cm. Cuts paper with a density of up to 400 g/m2 - scrap paper, photo paper, cardstock and designer cardboard.

If you are using a cartridge with a creasing line, we recommend using one side of the rubber plate along which the knife moves only for creasing. To do this, do not forget to turn it over every time and the fold line will always be straight.

Pros of the cutter:

• All cartridges are closed and can be changed very easily
• Presses the paper tightly
• Has a retractable ruler

Cons of the cutter:

• Sometimes it tears thin paper with a density of 80 g/m2
• It does not press the paper well against the top edge of the cutter and because of this, the cut is sometimes offset by 0.5-1 mm
• You need to press down firmly on the handle with the slider

Fiskars SureCut Paper Cutter - This cutter is also called a rotary cutter. An attachment with a blade is attached to the folding ruler, and a wire (string) is also stretched onto the ruler; it guides the blade when cutting. The nozzle moves up and down along a special recess on the working surface and cuts the paper. Cuts up to 5 sheets of paper with a density of 80 g/m2, designer cardboard, cardstock, scrap paper. The set includes 2 replaceable blades and a creasing attachment. The working surface of the cutter is 16x31 cm, there is a retractable ruler up to 38 cm. Markings in inches and centimeters are applied to the working surface, as well as standard paper sizes A5, A6, A7. The blades of the cutter are protected by a lock. There is a convenient transparent paper holder. Unfortunately, with frequent use, knives quickly become dull.

Classification according to the combustible gas used

Propane

Propane gas cutters are ideal for processing cast iron pipes and other products made from ferrous and non-ferrous metals. Propane gas cutters are rightfully considered the most reliable and safe and at the same time are able to provide maximum work productivity.

Acetylene

Acetylene gas cutters are used for cutting sheet metal and large parts. Such devices must be equipped with a special valve that regulates the speed and power of oxygen supply to the work area.

Universal

Universal injection-type gas cutters are the most in demand today. These devices allow you to use the power of the working gas if the pressure inside the housing is from 0.03 to 1.5 kgf/square centimeter. The universal cutter is simple and easy to use, has relatively small dimensions and is capable of cutting metal products in different directions. With its help, you can effectively process metal with a thickness of 3 to 300 mm in thickness.

Features of choice

To avoid mistakes, before purchasing a gas cutter, it is important to familiarize yourself with some of the design features of the device. This will allow you to understand what primary factors you need to pay attention to when choosing it.

Selection rules:

• Nipples - made of brass and aluminum, the former are considered more durable.
• Mouthpieces - the outer one is usually made of chrome bronze or pure copper (distinguished by a reddish tint). For acetylene devices, it is also desirable for the internal one to be copper; for others, the use of brass analogues is allowed.
• Connecting tubes are made of brass. At the same time, they should not have a decorative coating that can hide minor defects.
• Valve spindles are made of stainless steel; brass spindles have a short service life.
• Handle – aluminum is considered the best material, plastic is less wear-resistant. Its size must be at least 40 mm to have a comfortable girth.
• Cutter length – for cutting thick metal, as well as painted or oily materials, it is better to choose devices up to 1000 mm in size. In other cases, you can buy 500 mm burners.

Photo 5. Basic consumables for gas cutters

Also, when purchasing, it is recommended to take the tool in your hands and check it for ease of use. The productivity and time the master can work with a cutter without fatigue directly depends on this.

Pros and cons of gas cutters

The advantages of gas cutters include:

• The ability to effectively process metal with a thickness of up to 300 mm (depending on the modification and operating parameters of the equipment).
• Combustion stability of the exiting flame. The mixture is burned without popping or backfire.
• Ability to work with metal in any direction.
• Efficiency.
• High performance.
• Convenience and ease of equipment maintenance.
• Low cost of devices and components.

The disadvantages include:

• The likelihood of thermal deformation of the material.
• The need to refine the edges formed as a result of the cut.
• High risk of fire.
• Large cutting width, which makes it necessary to maintain allowances when carrying out marking work.
• Cannot be used with stainless steel.
• When working with thick metals, the taper of the cut becomes noticeable.

FELLOWES ELECTRON A4

The model has an unusual and stylish shape and is equipped with a round knife-blade. Thanks to the mechanical adjustment and direction of the rod, the cut occurs more smoothly and accurately. The knife extends only when cutting paper, so it will be very difficult to cut yourself with it. You can cut up to 10 sheets of A4 or other format at a time.

Pros:

1. The special shape increases ease of use;
2. Safety of use;
3. There is an automatic paper clamp;
4. The set includes a cutting unit with a straight and curved cutter.

Paper cutter KW-Trio 13021

Quite expensive, but very convenient, the paper cutter is presented in the form of a table with a work surface. The cutter can cut up to 10 sheets of A4 paper at a time. The maximum cutting length is 960 mm and the stack thickness is 1 mm. The model is produced in Germany, which speaks of its quality and reliability.

Pros:

1. Convenient design;
2. Robust and reliable design;
3. Precise cut;
4. Made in Germany.

Minuses:

1. High price.