Tutorials and precautions for making knives with sharp hacksaw blades

Introduction: There are many passionate craftsmen, or lovers of steel bars and wooden bars, who like to DIY some small tools by themselves. Of course, there is a lot of fun in this process, and at the same time, it is full of pride after completing a DIY product. Xiaotu knows that there are many knife enthusiasts hidden here, and also knows that there are many beginners who don't know how to start or how to do it.

So for this reason, we have specially compiled the tutorials and precautions for making knives with sharp steel saw blades!

DIY process of making a knife with a hacksaw blade

1. Tool preparation

1. Power tools

grinder

Grinders are inexpensive and are the machine of choice for concave grinding. It can also be used to create false edges and facets that are not too large. It is also mainly used for grinding and polishing.

Advantages: cheap price, small space occupation, many functions

Disadvantages: unsafe, no high-mesh abrasives (actually, there are, but expensive, it is emery wheel)

Uses: concave grinding / grinding / polishing

Belt machine

The belt machine is relatively expensive and is the machine of choice for flat grinding. It can also be used for simple concave grinding. Generally, it is not used for grinding, but can be polished

Advantages: Strong surface grinding ability, various mesh belts, relatively high safety

Disadvantages: expensive, bulky, relatively few functions

Uses: flat grinding/V-shaped grinding/polishing

2. Electric drill

bench drill

Advantages: easy to punch

Disadvantages: bulky, heavy, expensive

hand drill

Advantages: small size, light weight, low price

Disadvantages: high punching skills are required

Application: punch handle hole/blade hole/handguard hole/sheath hole, etc.

3. Non-electric tools

Diamond file

Uses: shaping, rough grinding, expanding hand holes, etc.

Whetstone

Uses: surface treatment, polishing, sharpening

handsaw

Uses: sawing steel/handle, etc.

paintbrush

Uses: drawing shapes on blanks

2. Blade material

The back material of the front steel saw blade is generally spring steel, and the tooth tip is generally M42 (W2Mo10Cr4Co8). Simple heat treatment can be done by yourself.

Suitable as a pocket knife.

3. Selection of handle material

wood

The wood is old wood, dense, fine fiber, not easy to deform, waterproof, good hand feeling, and good pattern. Common are: mahogany, ash, ebony, ebony, red sandalwood, cherry wood and so on.

Solid wood floors are not a good option.

horny

Horse deer antlers are high-quality materials, which have many advantages: no deformation, waterproof, dense texture, beautiful appearance, etc. The disadvantage is that it is expensive and not easy to buy.

The croissant is also the best material, but the disadvantage is that it is not thick enough.

Horns are medium grade. The yellow ox horn is not thick enough, only enough to make a small straight knife handle.

4. Craft DIY

1. Grinding first

There are three ways to get out the knife embryo

① Forging: If you can forge, don't look at the other two methods.

②Wire cutting: Take the drawing or CAD drawing to the wire cutting processing place to cut out the knife blank

③ Grinding: Use a paint pen to draw the shape of the knife on the blade, then use the outer circle of the grinding wheel of the grinder to grind out a large shape, and then use an electric grinder to correct the small corners.

It is recommended to use a grinder for shape grinding. I have no choice but to use a belt grinder. Take your time.

It is best to use 46# grinding wheel. Can quickly sharpen a knife to a large shape. If high-speed steel is used, the grinding wheel should be made of boron carbide or white corundum.

Highest grinding efficiency with least dust.

It is recommended to use a white corundum electric grinding head when using electric grinding to modify the shape. The emery wheel head is not easy to use, it is easy to take off the abrasive, and it is very expensive!

2. The method of punching holes with the front hacksaw blade

Wrap the part to be punched with scotch tape, Then use a knife to carefully dig out a round hole with the tape at the place where you plan to punch the hole, pay attention to the hole slightly smaller than the actual need. Both sides of the saw blade must be dug, and it must be symmetrical.

Then prepare a DC power supply (12V), connect the positive pole to the blade, put it into a plastic container with salt water, and put the negative pole inside, but do not touch the blade. The part of the blade that is not protected by tape should also not come into contact with salt water. When the power is turned on, the blade will slowly be corroded and holes will come out. (It takes about 3 or 4 hours).

3. Surface treatment

Surface treatment includes the edge of the knife and the surface of the knife. The incision after wire cutting is an irregular rough surface and needs to be polished. There are also scratches on the surface of the steel, which are also worn off.

The steps of surface treatment are:

If it is a sharp steel saw blade: first use the gold steel surface file to correct it, then use 150-300 mesh oil stone to push and grind it with both hands, and then use 600-800 mesh oil stone to grind. Each step has to polish the surface before proceeding to the next step. Surface treatment can be carried out very quickly by using some methods. If the diamond surface file is not used, the time will be doubled.

After grinding the knife embryo with 600 mesh oil stone, it should be very bright. Other steels that have not been heat-treated can also be ground by this method, but the process of grinding the diamond surface can also be omitted.

The next step is to polish the high-mesh abrasive belt on the belt machine or the cloth wheel on the grinder machine with about 400 mesh abrasive paste for fine polishing.

This step requires patience and slow progress. After polishing, it can be very bright, remove small convex surfaces on the surface, and reduce the conditions for water vapor deposition.

This step can also wait until the fine grinding stage after the blade is opened.

If you're patient, I'm all for doing 10 grinds, it's just a waste of time.

Forged surface is the best surface treatment. According to this process, it is satin. If you add finer oilstone and abrasive paste, you can get a mirror surface.

But the mirror has too many shortcomings.

4. Open front

This is the most important technology. The skills of experience cannot be expressed in words. If possible, I will open a special post to discuss it. Here are some principles.

Of course, if you are hard enough, you can try it yourself.

The techniques used for concave grinding, V-shaped grinding and flat grinding are the same, and there is no difference. Take concave grinding as an example:

The concave surface is ground on the outer circle of the grinding wheel.

First, grind out a slope of about 45 degrees in sections at the blade

Continuous grinding, connecting small slopes of segments

When the slope is evenly leveled, it needs to be carefully ground. The hand feeling is "press the small plane on the outer circle of the grinding wheel and drag the blade steadily with both hands", and you can get a flat and straight front line. Please feel it carefully here, yes top priority.

For the other front, use the grinding wheel on the other side of the grinder, and the left and right hands are interchangeable.

When encountering the arc at the tip of the knife, grind along the arc so that the arc is perpendicular to the cutting surface of the round surface of the grinding wheel, and the technique is coherent and completed in one go.

If the front line is not straight, it can be corrected repeatedly until there is no problem with the correction.

The last pass must be polished continuously, so that the front style is unified.

After the front line is basically completed in the last few times, it should be lightly ground after it is basically straight, so that even the 46# grinding wheel will grind out a bright front.

You must know that light is not only beautiful, but also a prerequisite for rust prevention.

5. False blade

There is no difference between the false blade on the belt machine and the general flat method, just pay attention to the contact surface.

The flat grinding of the grinding wheel is used on the grinder machine.

Generally, the false edge of the blade is attached to the plane of the grinding wheel, and the blade and the grinding wheel form an angle of 45 degrees (generally speaking, the angle can be trimmed). After connecting the contact surface, slowly attach it, and the hand should be steady, and it will be opened soon.

6. Tooth blade

Use a grinder to cut the toothed edge, use a grinding wheel with a thickness of 5, and use a diamond grinding pen to trim the outer circle into a semicircle and then use it to cut the toothed edge. But I strongly disagree with these methods, because a 5MM thick grinding wheel is very dangerous.

So don't try it, just do technical discussions.

Another effective method is to use an electric grinder, and use two cutting blades, one thick and one thin, to open the tooth blade. The method is to fix the knife with a vise, and use a hand-held electric grinder to cut the tooth edge.

7. Sharpening

When cutting the edge, it can be cut directly on the belt machine or directly on the grinder, but the technique is difficult to master and it is easy to overshoot. So I recommend two methods:

①Manual use of diamond file: Fix the knife vertically on the vise, press the diamond file on the blade at an angle of 30-40 degrees with both hands, push back and forth along the blade, and a very beautiful blade can be cut. Same on both sides.

②Use an electric grinder with a white corundum grinding head: fix the knife as above, hold the electric grinder on the blade with both hands at an angle of 30-40 degrees and gently push the blade along the direction. Because the speed of the electric grinder reaches 30,000 rpm, it is best to touch the blade lightly to avoid overshooting.

There are also methods such as using a fixed-angle sharpener, so I won’t go into details.

8. Fine grinding

The so-called fine grinding is to polish the newly opened front. Because in the opening item, I have asked for the last few times to be lightly ground, and the light that comes out is already bright enough. In this step, I need to use a step wheel and abrasive paste or a high-mesh abrasive belt for polishing to remove small contact surfaces and reduce the friction. Small water vapor absorption area.

Apply abrasive paste (white or green) on the step wheel, and polish it in the same way as a blade until it is polished.

All parts of the knife except the handle are polished for anti-rust treatment.

This method will not hurt the edge line and striker line.

9. Handle

Generally, the hilt has a full-cover type, a post-piece type, a through-handle keel, and a through-heart handle.

According to the real thing, we can guess the approximate connection method.

Mainly talk about some of the main and easily overlooked processes in the processing of wooden handles.

After the wooden handle is finished, it is best to soak it in wax, fry it, soak it in ammonia water, wax it, etc.

Can be waterproof, insect-proof, anti-deformation. For old wood, it can be polished directly with a step wheel dipped in oil, that is, it can be bright, and it can also seep oil at high temperature.

Precautions

I think the most important thing is safety, everyone is here for fun, if it is not safe, it will be bad.

A grinder is an extremely dangerous type of power tool. Be sure to pay attention when using:

1. People cannot stand on the circular radiation surface of the grinding wheel.

2. The grinding wheel must not be used if it has cracks.

3. When starting a new machine, people must avoid it for a period of time, and then use the grinder after the operation is stable.

4. Do not touch the grinding wheel violently when loading, and load slowly.

5. The protective cover of the grinder must be installed and installed.

6. If you hear abnormal noise, you must stop the machine immediately.

7. The grinding wheel must be shut down for half an hour when it is used for half an hour to one hour.

8. If possible, all diamond wheels are used. Although it is expensive, it improves the safety factor.

After reading such a detailed tutorial and precautions for making a knife with a hacksaw blade, are you eager to try to make a majestic knife yourself? Dear knife enthusiasts and big men who like DIY, don't hesitate any longer. After reading the tutorial, don’t hurry to prepare your tools, understand the tutorial, and follow the above steps step by step to sharpen your own knife. Let's enjoy the fun of DIY together!