Question 1

How to adjust the cone angle of a Rockwell hardness tester?

Accepted Answer

The superficial Rockwell hardness value increases as the cone angle of the diamond indenter increases. For the 30N and 45N scales, angular variations have a significant impact on low hardness values but a smaller impact on high hardness values. For the 15N scale and the high-value hardness blocks of the 30N scale, there is almost no impact.

Our company is a firm specializing in providing metal detection and analysis instruments, producing high-quality products such as metallographic pre-processing equipment, metallographic cutting machines, metallographic mounting machines, micro-Vickers hardness testers, and Rockwell hardness testers. Welcome to Taiwan Nakazawa Co., Ltd. to make your purchase.

Question 2

Does the loading speed of a Rockwell hardness tester affect the hardness value?

Accepted Answer

The impact of loading speed on hardness values: When the application speed of the main load of the Rockwell hardness tester is changed from 2 seconds to 12 seconds, the impact on the hardness values is 0.2 HRC for low hardness values, 0.4 HRC for medium hardness, and 0.6 HRC for high hardness.

Our company, Taiwan Nakazawa Co., Ltd., specializes in the production of precision metallographic testing equipment, such as metallographic cutting machines, metallographic grinding and polishing machines, Vickers hardness testers, metallographic mounting machines, and other precision equipment. Friends in need are welcome to come and make a purchase.

Question 3

How to choose the right Rockwell hardness tester?

Accepted Answer

Taiwan Nakazawa Co., Ltd. suggests for you:
1. If you want to choose a budget-friendly option, then choose: the analog type with manual loading, which is solid and durable.
2. If you want to choose equipment with a high price-performance ratio, then choose: the digital Rockwell hardness tester.
3. If you require a high degree of automation, then choose: the fully automatic Rockwell hardness tester.
4. If you need to test large or heavy parts that are convenient to test like a desktop computer, then choose: the portable Rockwell hardness tester.

Question 4

What are the techniques for using a portable Rockwell hardness tester?

Accepted Answer

Taiwan Nakazawa Co., Ltd. answers for you: Portable Rockwell hardness testers are divided into different categories based on the type of hardness tester, and the portable Rockwell hardness tester is one of them.
The Rockwell hardness tester is a new type of handheld, multi-functional dynamic hardness testing instrument.
The portable Rockwell hardness tester is a hardness tester designed using advanced microprocessor technology. It features high testing precision, stable and reliable performance, small size, easy operation, convenient portability, and a wide measurement range. It is suitable for rapid hardness testing of metal materials, especially for on-site hardness testing of large components and non-removable parts. It is an ideal hardness testing instrument for industries such as molds, machinery, machine tools, hardware, heat treatment, forging, and special steel.

Question 5

What are the applications of Rockwell hardness testers in the heat treatment industry?

Accepted Answer

Rockwell hardness testers applied to testing heat-treated workpieces: Surface quenching and tempering heat treatment is usually carried out using induction heating or flame heating. The main technical parameters are surface hardness, local hardness, and effective hardening layer depth. Hardness testing can utilize a Vickers hardness tester, or a Rockwell or superficial Rockwell hardness tester.
The Rockwell hardness tester is an important means of testing the surface hardness of heat-treated workpieces. It can select a test force of 0.5 ~ 100kg and test surface hardened layers as thin as 0.05mm. Its precision is very high, and it can distinguish minor differences in the surface hardness of heat-treated workpieces.

Our company, Taiwan Nakazawa Co., Ltd., specializes in the production of precision metallographic testing equipment, such as metallographic cutting machines, metallographic grinding and polishing machines, Vickers hardness testers, metallographic mounting machines, and other precision equipment. Friends in need are welcome to come and make a purchase.

Question 6

What components can a Rockwell hardness tester be used to test?

Accepted Answer

1. Hardness testing of machine tool guide rails and automobile chassis.
2. Installed machinery or permanently assembled components.
3. Workpieces with very narrow testing spaces, such as mold cavities.
4. Rapid inspection of multiple measurement locations across a wide area on large workpieces.
5. Failure analysis of pressure vessels, turbo-generators, and other equipment.
6. Production lines for bearings and other parts.
7. Material differentiation in metal material warehouses.
8. Quality control of heat-treated workpieces.
9. Requirements for formal original records of test results.
10. Realization of mutual conversion between six types of hardness (HL, HRB, HRC, HB, HV, HS) and mutual conversion between hardness and tensile strength.
11. Display of rich information such as measured value, average value, date, impact direction, number of tests, test material, and hardness scale.

The hardness testers produced by our company, Taiwan Nakazawa Co., Ltd., feature high precision and stable performance. We offer a complete range of specifications and models suitable for testing various products in all walks of life.

Question 7

What are the characteristics of a Rockwell hardness tester?

Accepted Answer

Rockwell hardness testers feature simple operation, convenient use, low price, rapid measurement, and the ability to directly read hardness values. Using a superficial Rockwell hardness tester, rapid and non-destructive piece-by-piece inspection can be performed on batches of surface heat-treated workpieces. This point is of great significance for metal processing and machinery manufacturing plants.
When the surface heat-treated hardened layer is thick, a Rockwell hardness tester can also be used. When the thickness of the heat-treated hardened layer is between 0.4 and 0.8 mm, the HRA scale can be adopted; when the thickness of the hardened layer exceeds 0.8 mm, the HRC scale can be adopted.

The hardness testers produced by our company, Taiwan Nakazawa Co., Ltd., feature high precision and stable performance. We offer a complete range of specifications and models suitable for testing various products in all walks of life.

Question 8

What factors affect the performance of a Vickers hardness tester?

Accepted Answer

Taiwan Nakazawa answers for you, regulations regarding ball indenters:
(1) The steel ball diameter must be selected according to regulations. Brinell hardness values obtained under different steel ball diameter conditions vary from each other and cannot be compared.
(2) The Vickers hardness of the steel ball should be no less than 850HV10, and the Vickers hardness of the cemented carbide ball should be no less than 1500HV10.
(3) The surface roughness Ra of the steel ball should be no greater than 0.04μm. Regarding the steel ball: besides the ball diameter, the Vickers hardness value is also related to the ball hardness and ball surface roughness, etc.
Regarding the specimen: the Vickers hardness value is related to the specimen material, specimen shape, specimen surface roughness, and specimen temperature, etc.

Question 9

What are the main testing ranges of a micro Vickers hardness tester?

Accepted Answer

Ferrous metals, non-ferrous metals, IC wafers, surface coatings, laminated metals; glass, ceramics, agate, gemstones, etc.; hardness testing for the depth and gradient of carbonized layers and quench-hardened layers. Hardware processing, electronics industry, mold accessories, and the watch and clock industry.

Our company is a firm specializing in providing metal detection and analysis instruments, producing high-quality products such as metallographic pre-processing equipment, metallographic cutting machines, metallographic mounting machines, micro-Vickers hardness testers, and Rockwell hardness testers. Welcome to Taiwan Nakazawa Co., Ltd. to make your purchase.

Question 10

What are the advantages of a Vickers hardness tester?

Accepted Answer

The indentation of the Vickers hardness tester is square with a clear profile, and the measurement of the diagonals is very accurate. Therefore, the Vickers hardness tester is generally a hardness measurement method with high precision among commonly used hardness testing methods, and its repeatability is also very good, a point that the Brinell hardness tester cannot surpass.
The Vickers hardness tester can measure almost all metal materials currently used in industry, from very soft metal materials (with only a few Vickers hardness units) to very hard metal materials (over 3,000 Vickers hardness units). A major advantage of the Vickers hardness tester is that the hardness value basically has no relationship with the magnitude of the test force. As long as the material is very uniform in hardness, the test force can be chosen arbitrarily, yet the measured hardness value remains unchanged. This is equivalent to having a unified scale within a very broad range of hardness.

The hardness testers produced by our company, Taiwan Nakazawa Co., Ltd., feature high precision and stable performance. With a complete range of specifications and models, they are suitable for product testing across all industries and fields.

Question 11

What are the various factors that affect the testing performance of a Vickers hardness tester?

Accepted Answer

Human Error:
1. Caused by insufficient operator proficiency, lack of practical experience, or improper operation; the equipment should be used under the guidance of experienced personnel.
2. Loading too fast or having a short dwell time will result in higher hardness readings for low-hardness parts, whereas loading too slowly or having a long dwell time will result in lower hardness readings. During operation, loading should be smooth and maintained for a specific duration.

Influence of the Hardness Tester Indenter:
1. The indenter does not meet technical requirements or has worn down after a period of use. If the operator cannot judge the condition of the indenter, it should be sent to a metrological testing institution for appraisal.
2. If the strength and hardness of the steel ball indenter are insufficient, it is prone to deformation. When a steel ball is flattened and undergoes permanent deformation into an oval shape: if the short axis is perpendicular to the part surface, the indentation will be shallow and the indicated value will be high; if the long axis is perpendicular to the part surface, the indentation will deepen and the indicated value will decrease. The allowable tolerance for the steel ball is 0.002mm.

Our company, Taiwan Nakazawa Co., Ltd., specializes in the production of precision metallographic testing equipment, such as metallographic cutting machines, metallographic grinding and polishing machines, Vickers hardness testers, metallographic mounting machines, and other precision equipment. Friends in need are welcome to come and make a purchase.

Question 12

Does a Vickers hardness tester inherently contain errors?

Accepted Answer

Taiwan Nakazawa Co., Ltd. answers for you: Yes, there will be [errors], generally divided into two types:
1. Each hardness scale is actually a range, depending on the selection. For example, if the hardness is greater than HRB100, the HRC scale should be used for testing; if the hardness is less than HRC20, the HRB scale should be used. Because outside of its predetermined testing range, the sensitivity of the hardness tester is poor and the hardness values are inaccurate, it should not be used. Other hardness testing methods also provide appropriate calibration standards. When calibrating a hardness tester, both sides of the standard block cannot be used because the hardness of the standard surface and the back surface is not necessarily consistent. Generally, the calibration block is required to be valid for one year from the date of calibration.
2. When replacing the indenter or the anvil, pay attention to wiping the contact areas of different parts clean. After replacement, test several times using a steel sample of a certain hardness until the hardness values obtained twice in succession are the same. The purpose is to ensure that the contact parts of the indenter or anvil and the testing machine are tightly pressed and in good contact, so as not to affect the accuracy of the test results.

Question 13

What kinds of errors exist when operating a Vickers hardness tester?

Accepted Answer

1. Hardness tester adjustment: when starting to measure hardness, the first several test points are not used. Due to poor contact between the sample and the anvil, the measured values are inaccurate. After these point tests are completed, the hardness tester reaches a normal operating mechanism state; then, formal testing is performed on the sample, and the measured hardness values are recorded.
2. In the case of specimens, hardness values are typically tested from at least three different parts, and the average value is taken as the hardness of the test piece.
3. For specimens with complex shapes, corresponding support blocks of different shapes must be used, and testing can only be conducted after they are fixed. Circular specimens should generally be tested in a V-shaped groove.

Our company is a firm specializing in providing metal detection and analysis instruments, producing high-quality products such as metallographic pre-processing equipment, metallographic cutting machines, metallographic mounting machines, micro-Vickers hardness testers, and Rockwell hardness testers. Welcome to Taiwan Nakazawa Co., Ltd. to make your purchase.

Question 14

What safety precautions should be taken when selecting a Vickers hardness tester?

Accepted Answer

1. Considerations for selection: When purchasing a Vickers hardness tester and testing services, buying from the manufacturer or a designated local manufacturer with service agent capabilities can save you a lot of trouble in after-sales service.
2. Matters to note in Vickers hardness tester selection: Try to purchase a micro-Vickers hardness tester, because micro-Vickers hardness testers have wider applications than small-load Vickers hardness testers and can measure thinner workpieces; even if they are not currently in use, perhaps they will be in the future.
3. Precautions for Vickers hardness tester selection: The measurement precision requirements for Vickers hardness testers are actually quite similar; the differences lie only in a few aspects such as the humanization of the operating system interface, the user's feel, and the clarity of the eyepiece.

Our company, Taiwan Nakazawa Co., Ltd., specializes in the production of precision metallographic testing equipment, such as metallographic cutting machines, metallographic grinding and polishing machines, Vickers hardness testers, metallographic mounting machines, and other precision equipment. Friends in need are welcome to come and make a purchase.

Question 15

What are the applications of digital Rockwell hardness testers?

Accepted Answer

The digital Rockwell hardness tester has a wide range of application capabilities. It is suitable for analyzing and determining the Vickers hardness of various heat treatments, carbonized layers, quench-hardened layers, surface coatings, steel, and non-ferrous metals. It can also measure the microhardness of tiny, thin specimens and surface-plated specimens, as well as the Knoop hardness of brittle and hard materials such as glass, ceramics, agate, and gemstones. It is an ideal hardness testing instrument for scientific research institutions, enterprises, and quality inspection departments to conduct research and material testing.

The hardness testers produced by our company, Taiwan Nakazawa Co., Ltd., feature high precision and stable performance. We offer a complete range of specifications and models suitable for testing various products in all industries.

Question 16

What information is displayed in the notification from the digital Rockwell hardness counter code display?

Accepted Answer

(1) Periodically inject a small amount of oil into the contact surface of the screw and handwheel.
(2) Before using the digital Rockwell hardness tester, the top surface of the screw, the working level table, and the end faces should be wiped clean.
(3) Regularly check the precision of the hardness tester with standard hardness blocks; testing on the support surface is strictly prohibited.
(4) When the standard hardness block has burrs, use an oilstone to grind the supporting surface. At different testing positions, the block should be dragged across the table and should not be removed from the working surface.

This digital Rockwell hardness tester of our company is a representative product, a model that has achieved an extremely high market share with an overwhelming advantage. It is suitable for metal and scientific research hardness testing in various fields. Friends in need are welcome to visit Taiwan Nakazawa Co., Ltd. to learn more details.

Question 17

What precautions should be taken when routinely maintaining a Rockwell hardness tester?

Accepted Answer

Rockwell hardness testers have been widely applied in industrial production, becoming a primary means of inspecting product quality and determining reasonable processing techniques. They can test various ferrous and non-ferrous metals, and the hardness of quenched steel, tempered steel, annealed steel, surface-hardened steel, sheets of various thicknesses, cemented carbide materials, powder metallurgy materials, and thermal spray coatings. Therefore, the daily maintenance of the Rockwell hardness tester requires attention to the following:
1. When the hardness tester is not in use for a long time, the machine should be covered with a dust cover.
2. Periodically inject a small amount of machine oil into the contact surface between the lead screw and the handwheel.
3. Before using the hardness tester, the top surface of the lead screw and the upper end surface of the worktable should be wiped clean.

Taiwan Nakazawa Co., Ltd. provides on-site installation services by dedicated personnel, so you can purchase and use our products with confidence!

Question 18

If the Rockwell hardness tester shows a large error how should it be maintained and handled?

Accepted Answer

Taiwan Nakazawa Co., Ltd. suggests for you:
(1) You can remove the worktable and check if its contact surface with the screw is clean.
(2) Check whether the screw protective sleeve is propping up the worktable.
(3) Check whether the indenter is damaged. If the indicator pointer starts to rotate very quickly and then rotates slowly when the main test force is applied, it indicates that there is too little machine oil in the buffer. At this time, you can lift the felt pad at the upper end of the buffer and slowly inject clean machine oil. At the same time, pull and push the handle several times to move the piston up and down repeatedly to completely exhaust the air in the buffer, until oil overflows from the top when the piston sinks to the bottom.

Question 19

How should one choose a hardness tester?

Accepted Answer

As far as hardness testers are concerned, the key point lies in the precision issue during hardness testing. Generally speaking, hardness testing can utilize a Vickers hardness tester, or a Rockwell or superficial Rockwell hardness tester. This depends on the situation; if very high precision is required, a Vickers hardness tester must be selected. The choice of test force (scale) is related to the effective hardened layer depth and the surface hardness of the workpiece.
The Vickers hardness tester is an important means of testing the surface hardness of heat-treated workpieces. It can select a test force of 0.5 ~ 100kg and test surface hardened layers as thin as 0.05mm. Its precision is very high, and it can distinguish minor differences in the surface hardness of workpieces. In addition, the effective hardened layer depth must also be detected by a Vickers hardness tester. Therefore, for units performing surface heat treatment processing or extensively using surface heat-treated workpieces, it is necessary to be equipped with a Vickers hardness tester.

Our company, Taiwan Nakazawa Co., Ltd., specializes in the production of precision metallographic testing equipment, such as metallographic cutting machines, metallographic grinding and polishing machines, Vickers hardness testers, metallographic mounting machines, and other precision equipment. Friends in need are welcome to come and make a purchase.

Question 20

What are the effects of the load time on the Vickers hardness tester?

Accepted Answer

Taiwan Nakazawa Co., Ltd. answers for you: The load should be applied smoothly and slowly, without any vibration or shock phenomena.
(1) A faster loading speed will lead to lower hardness values because the plastic deformation produced at this time is not only the static indentation of the load, but also involves a partial dynamic force, which generates kinetic energy and results in greater material deformation. This influence increases as the load decreases, the hardness range of the test specimen increases, and the mass of the moving parts in the loading mechanism increases.
(2) The loading speed should also not be too slow. Excessively prolonging the indenter's indentation time, especially when the dwell time is short, will result in the load not being maintained for the specified duration, thereby creating new deviations.
(3) A loading speed that is too slow is also susceptible to interference from external conditions. Generally, it must not exceed 50 μm/s. Based on the regulations of standard test methods from various countries worldwide, loading speeds are mostly within the range of 15-70 μm/s. The loading speed must be determined according to the loading method and the characteristics of the loading mechanism; in some cases, it is determined by the turning time of the loading handle. Regardless of the form, the necessary condition must be met: the loading speed should reach a point where it does not affect the increase in indentation size.

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