Category Archives: Blog

Our company promoted the 34CrNiMo6 steel material for the SPECIAL OFFER. The diameter is 35-130mm.

34CrNiMo6 steel after tempering, it is used to make important parts. The parts require good plasticity, high strength and large size. Such as high-load shafts in heavy machinery, steam turbine shafts with a diameter greater than 250mm. It also be used for rotor shafts and blades with operating temperatures exceeding 400°C. In addition, this steel can also be used to make important parts with special performance requirements after nitriding.

Regarding for this steel material, I have the experience to share with you guys, so that you could avoid the cheated by some not reliable suppliers.

Several years ago, I visited a new customer in abroad. And when we talked about the 34CrNiMo6 steel price, his first reaction was your price is too higher than other supplier. In fact, usually for the steel material price, it is very transparent in China steel market. It will be not a very big difference if it is the true material as itself. When he showed me some part info about his contract, I found what was the real reason. And his other supplier wrote the grade name 34CrNiMo6 steel on the contract, but the chemical composition did not match the 34CrNiMo6 exactly. The composition is for 4340 steel! So that supplier supplied the 4340 to him actually instead of 34CrNiMo6. It made the price different.

Therefore, hereby we sincerely have the friendly reminding to our customer friends. Please do not just focus on the price. You have to double check all the details before you sign the order contract. If you are not professional on it, you’d better to find the reliable supplier to cooperate.
Our OTAI Special steel with ISO certified origin from the brand mills in China, produced in a rigorous system and with traceability. We build ties with our customers and brand mills based on the pillars of ethics and transparency. OTAI do not give up honesty and cultivate relationships of loyalty and trust that aim at a prosperous partnership for both.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

8620 steel and 1045 steel

Otai exports various tool steel and alloy to more than 30 countries from Europe and America, Middle East, and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 8620 steel and 1045 steel’s difference and its application.

8620 is the structural steel with the hardenability guaranteed by American standard, and the standard is as follows: ASTM A29/ A29m-2015 (hot forged and cold processed carbon steel and alloy steel bar).

It has high hardenability, no tempering brittleness, good weldability. Also, it has little tendency to form a cold crack, good maintainability, and cold strain plasticity. Generally used in quenching and tempering or carburizing state, used for manufacturing small and medium-sized automobile, tractor engine, and gear in the transmission system. Also, it can be used for oil drilling and metallurgy open mine cone bit teeth and teeth body. Manufacturing steam turbine gear whole rotor internal combustion engine connecting rod valve section forgings all can be made by 8620 steel. At the same time, the surface of 8620 steel after carburizing heat treatment has relatively high hardness, wear-resistance, and contact fatigue strength. While the core retains good toughness and can withstand high impact load. It can be used as automobile bearing, spindle, gear, mechanical parts, and other impact-resistant, wear-resistant workpieces.

ASTM SAE AISI 1045 steel is one of the commonly used medium carbon steels with an average carbon content of 0.45%.

It has medium tensile properties, good strength, toughness, and wears resistance. It can be treated by annealing, flame treatment, or induction hardening. C1045 is also known as 1045 cold-rolled steel (cold worked), and 1045 hot rolled steel is known as 1045 HR. AISI SAE 1045 material is widely used in industrial applications where higher wear resistance and strength are required. Typical applications including Light gears, shafts, axles, spindles, pins, guide rods, connecting rods, bolts, worms, crankshafts, machine components, etc.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

4340 steel and 4140 steel

Otai exports various tool steel and alloy to more than 30 countries from Europe and America, Middle East and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 4340 steel and 4140 steel’s difference and its application.

4340 alloy structural steel belongs to gear steel.

It is used for important tempering parts that require good toughness, high strength, and large size, such as heavy machinery high-load shaft, turbine shaft with a diameter greater than 250mm, helicopter rotor shaft, turbojet engine turbo shaft, blade, high-load transmission parts, crankshaft fasteners.Gear, etc. It can also be used for rotor shaft and blade with an operating temperature over 400℃. It can also be used to make important parts with special performance requirements after nitriding treatment, which can be used for ultra-high strength steel after low-temperature tempering or isothermal quenching.

4140 steel, the steel has good workability, machining deformation of small, anti-fatigue performance is quite good.

On the hardenability of steel, 4140 heat treatment has good strength and good comprehensive mechanical properties, good manufacturability, high yield. The highest temperature is 427 degrees Celsius. 4140 strength, high hardenability, and good toughness, quenching deformation of small, high temperature creep rupture strength, and high. It is used for manufacturing forgings with higher strength and larger tempering cross section than 35CrMo steel, such as big gear for locomotive traction, supercharger drive gear, rear axle, connecting rod and spring clamp with great load, also can be used for drilling pipe joint and fishing tool of oil deep well below 2000m, and can be used for bending machine mold, etc.

Otai does not act as material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

4340 steel and 8620 steel

Otai exports various tool steel and alloy to more than 30 countries from Europe and America, Middle East, and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 4340 steel and 8620 steel’s difference and its application. 

4340 alloy structural steel belongs to gear steel.

It is used for important tempering parts that require good toughness, high strength, and large size. Such as heavy machinery high-load shaft, turbine shaft with a diameter greater than 250mm. It also used for making helicopter rotor shaft, turbojet engine turboshaft, blade, high-load transmission parts, crankshaft fasteners and etc. It can also be used for rotor shaft and blade with an operating temperature over 400℃. It can also be used to make important parts with special performance requirements after nitriding treatment. Which can be used for ultra-high-strength steel after low-temperature tempering or isothermal quenching.

8620 is the structural steel with the hardenability guaranteed by American standard, and the standard is as follows: ASTM A29/ A29m-2015 (hot forged and cold processed carbon steel and alloy steel bar).

It has high hardenability, no tempering brittleness, good weldability, little tendency to form cold crack, good maintainability, and cold strain plasticity. Generally used in quenching and tempering or carburizing state, used for manufacturing small and medium-sized automobiles, tractor engine, and gear in the transmission system. It also used in oil drilling and metallurgy open mine cone bit teeth and teeth body, manufacturing steam turbine gear whole rotor internal combustion engine connecting rod valve section forgings. At the same time, the surface of 8620 steel after carburizing heat treatment has relatively high hardness, wear-resistance and contact fatigue strength. While the core retains good toughness and can withstand high impact load. It can be used as automobile bearing, spindle, gear, mechanical parts, and other impact-resistant, wear-resistant workpieces.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

Since 2018, OTAI has increased the investment in 4140 prehardened plate, and now the daily inventory is kept at more than 800 tons. All regular size 12-180mm thickness plate is available to ship any time. The warehouse can start the delivery procedure immediately after ordering if not especially big volume. 4140 prehardened plate is 2000-2300mm wide and 3000-5800 long. It can be cut into the size required by customers. OTAI 4140 prehardened plate stock, can support 2-3 days quickly delivery.

Problems of 4140 prehardened plate in China market

First, both good and bad quality are in the market. Some supplier provide 42CrMo materials to replace the American Standard 4140. In fact, the chemical composition of the two materials is different. When foreign buyers receive the goods, the difference can be found by testing the composition. What OTAI provide is the real American Standard 4140.

Second, 4140 Prehardened plate require quenching and tempering process. Some heat treatment plant cannot control the temperature and hardness very well. It lead to the material mechanical properties not meet standard, and eventually there will be various problems in the end use. OTAI 4140 prehardened plate,is completely controlled according to the AISI Standard. All mechanical properties, including tensile strength, yield strength, elongation, shrinkage, impact energy and hardness, are tested and delivered only when they meet the standard completely.

Third, the delivery time is very long, even if the supplier promised a very short delivery time. In fact, they did not have so much inventory, and they had to transfer goods from other stockiest, agent or steel mills. In fact, few stockers can prepare all sizes all the time, and the size of out of stock will greatly extend the delivery time. Therefore, suppliers often say that 7-day delivery, in fact, they may not be able to deliver in one month, consider the long time sea transportation time, oversea buyers have missed the best sales opportunity.

Why OTAI can support quickly shipping time?

The 4140 plate is the core product of OTAI, with an average daily stock of more than 800 tons. If each dimension is lower than the limited inventory standard, it will be replenished in time to ensure that each thickness can be delivered at any time. Foreign customers often put together a container in multiple sizes. Other steel stockers need long time to gather the sizes together. However, it is very easy for OTAI to proceed such orders. For the hot-rolled black 4140 preharded plate, it takes 2-3 days to complete the shipping mark and pre delivery inspection, and then it can be delivered.

OTAI Customer Story

Half a year ago, one of our Argentina customer inquired about 4140 prehardened plate, black surface, without milling and cutting, and the thickness range is 30-100mm. This kind order is very simple for our company, and the price is very competitive as well, which is a very corresponding customer for us. The customer was satisfied with our price, asked how long the delivery time was, and I replied 2-3 days before delivery. But no further reply since then.

Eager to know why, I called my clients at night (during the day in Argentina). The customer said hat according to his previous experience, Chinese suppliers deliver goods within 30-45 days, and it is impossible to deliver goods to him within two or three days. He felt that the information I might tell lie to get his order, and then he worried about the quality and business safety with us. Although he was satisfied with the price, he still had to consider it. I learned about the customer’s concerns, and things became easier.

The next day, I went to the warehouse and took a lot of photos and videos of 4140 prehardened plate. I was in the video, show him our warehouse material, saw milling machine, cutting machine and inspection machine and test process. With these evidence, the customer dispelled all concerns, placed an order smoothly, and got the goods very quickly from us. Now this customer buy 4140 prehardened plate from us regularly.

Why choose OTAI?

For the 4140 prehardened plate, OTAI have obvious advantage compared with our competitors, because OTAI focuses on the 4140 plate, and there is no second one in China. Our company not only guarantees the complete size with sufficient stock, but also ensures that the chemical composition and all mechanical properties are 100% in line with AISI standard. If you want to purchase 4140 plate, OTAI is your rather good choice.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

4140 plate Overseas Exclusive Agent on behalf of Otai Special Steel to sells 4140 plate outside of China . In 2020 , Otai Special Steel have big plan of 4140 plate . We keep daily inventory of 800 tons , and want to found our 4140 plate Overseas Exclusive Agent in every country or every regions outside of China .

We provide the best quality production and most competitive price . The fast delivery and the best supporting services . Hope that all the strength company and quality stockbrokers to join us . And start our win-win cooperation business relationships from here in today .

Why Otai Special Steel want to actualized 4140 plate Overseas Exclusive Agent out of China ? And Why we have this capability to achieve this project ?

1. Otai Special Steel have specialized in provide 4140 plate  . We have  export steel experience all over the world for more than 16 years . We have more than 100 repeat customer from Spain , Argentina , Chile , Ecuador , Brazil , Italy  , Ukraine , Qatar , Turkey , U.A.E , Egypt ,  Kuwait , Bulgaria , Japan , Thailand , Singapore , Malaysia , Vietnam … … . And all our steel have provided to the steel giants like Dyson Krupp, Mitsubishi … …
2. Otai Special Steel was the sole supplier of more than 800 tons 4140 plate of inventory in South China . From June , our dailly warehouse number may exceed 800 tons . Which size was sold out , we may replenish inventory accordingly . We will make sure any size any time have more stock list . I promise no other supplier could do this .
3. Excellent quality . BaoSteel makes the quality originals the best. And Otai Special Steel has our own quality inspection instrument. Hand-held spectrometer use on Chemical composition analysis per heat and conform to the standard . UT test to check the material inside quality. Hardness test to guarantee the requirement. Physical checking to ensure tolerance .
4. The best service from Otai Special Steel  ensure that . All the other difficult could be handle by Otai before shipment. The end-use guiding. Technical problems in the use of processing . Delivery problems. Shipping documents problems …… All the problems we could solve for you.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

4140 steel and 8620 steel

Otai exports various tool steel and alloy to more than 30 countries from Europe and America, Middle East, and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 4140 steel and 8620 steel’s difference and its application. 

4140 steel, the steel has good workability, machining deformation of small, anti-fatigue performance is quite good.

On the hardenability of steel, 4140 heat treatment has good strength and good comprehensive mechanical properties, good manufacturability, high yield. The highest temperature is 427 degrees Celsius. 4140 strength, high hardenability, and good toughness, quenching deformation of small, high temperature creep rupture strength, and high. It is used for manufacturing forgings with higher strength and larger tempering cross-section than 35CrMo steel, such as big gear for locomotive traction, supercharger drive gear, rear axle, connecting rod and spring clamp with great load, also can be used for drilling pipe joint and fishing tool of oil deep well below 2000m, and can be used for bending machine mold, etc.

8620 is the structural steel with the hardenability guaranteed by American standard, and the standard is as follows: ASTM A29/ A29m-2015 (hot forged and cold processed carbon steel and alloy steel bar).

It has high hardenability, no tempering brittleness, good weldability, little tendency to form cold crack, good maintainability, and cold strain plasticity. Generally used in quenching and tempering or carburizing state, used for manufacturing small and medium-sized automobile, tractor engine and gear in the transmission system, oil drilling and metallurgy open mine cone bit teeth and teeth body, manufacturing steam turbine gear whole rotor internal combustion engine connecting rod valve section forgings. At the same time, the surface of 8620 steel after carburizing heat treatment has relatively high hardness, wear-resistance, and contact fatigue strength, while the core retains good toughness and can withstand high impact load. It can be used as automobile bearing, spindle, gear, mechanical parts, and other impact-resistant, wear-resistant workpieces.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

9310 steel and 8620 steel

Otai exports various tool steel and alloy to more than 30 countries from Europe and America, Middle East, and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 9310 steel and 8620 steel’s difference and its application.

9310 Alloy Steel (also known as AISI 9310 steel) is low alloy steel composed primarily of nickel and chromium.

The standard is ASTM A322. It shows high hardenability, high core hardness, and high fatigue strength. It also possesses solid ductility, weldability, and machinability properties. Its Components with a large cross-section requiring high toughness and core strength, It Mainly used for such as critical aircraft engine gears, automotive applications, structural components, gears, rods, heat-treatable shafts, high-performance helicopter transmission gears, and other components.

8620 is the structural steel with the hardenability guaranteed by American standard. Its standard is as follows: ASTM A29/ A29m-2015 (hot forged and cold processed carbon steel and alloy steel bar).

It has high hardenability, no tempering brittleness, good weldability, little tendency to form a cold crack, good maintainability, and cold strain plasticity. Generally used in quenching and tempering or carburizing state, used for manufacturing small and medium-sized automobile, tractor engine and gear in the transmission system, oil drilling and metallurgy open mine cone bit teeth and teeth body, manufacturing steam turbine gear whole rotor internal combustion engine connecting rod valve section forgings. At the same time, the surface of 8620 steel after carburizing heat treatment has relatively high hardness, wear-resistance, and contact fatigue strength, while the core retains good toughness and can withstand high impact load. It can be used as automobile bearing, spindle, gear, mechanical parts, and other impact-resistant, wear-resistant workpieces.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

9310 and Mild steel

Otai exports various 9310 and Mild steel to more than 30 countries from Europe and America, Middle East, and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards. Today we will talk about 9310 and Mild steel’s difference and its application. 

9310 Alloy Steel (also known as AISI 9310 steel) is low alloy steel composed primarily of nickel and chromium.

The standard is ASTM A322. It shows high hardenability, high core hardness, and high fatigue strength. It also possesses solid ductility, weldability, and machinability properties. Its Components with a large cross-section requiring high toughness and core strength, It Mainly used for such as critical aircraft engine gears, automotive applications, structural components, gears, rods, heat-treatable shafts, high-performance helicopter transmission gears, and other components.

Mild steel is also known as mild steel because of its low strength and hardness.

It includes most ordinary carbon structural steel and a part of high-quality carbon structural steel, most of which are not used for engineering structural parts by heat treatment, some by carburizing and other heat treatment for mechanical parts requiring wear resistance.

The annealing structure of low carbon steel is ferrite and a small amount of pearlite. Therefore, its cold forming ability is good, can be used to roll, bend, stamping, and other methods of cold forming. The steel also has good weldability. The carbon content ranges from 0.10% to 0.30%. Low carbon steel is easy to be processed such as forging, welding, and cutting. It is often used to make chains, rivets, bolts, and shafts.

Otai does not act as a material handler. We possess proprietary technology and continuously iterates. We undertake every order to end and solve customer’s problems without any hesitation on responsibility. When customized special steel is hard to get, Otai settles satisfactorily completely.

4140 plate fast delivery  from Otai Special Steel in 7-10 days . Otai Special Steel was the sole supplier of more than 500 tons 4140 plate of inventory in South China . From June , our monthly warehouse number may exceed 500 tons . Which size was sold out , we may replenish inventory accordingly . We will make sure any size any time have more stock list . I promise no other supplier could do this .

Otai Special Steel have specialized in provide 4140 plate fast delivery . We have more than 16 years export experience . Also professional for 4140 / 8620 /4340 / 34CrNiMo6 / M2 / 18CrNiMo7-6 round bar … … . Our steel sold to all over the world . And our repeat customer from every where on the earth .

Why Otai Special steel could provide 4140 plate fast delivery in 7-10 days? And why so many repeat customer purchase 4140 plate from us. Why Dyson Krupp , Mitsubishi want to co-operate with Otai Special Steel?

1. Otai Special steel has adequate supply was first step to ensure 4140 plate fast delivery. All 4140 plate in warehouse comes from BaoSteel . Baosteel was the best steel mills in China. The quantities for 4140 plate in our warehouse arrived 500Tons, and from June, exceed to be more than 500Tons. All the sizes required by our customers are available in our warehouse.
2. Excellent quality was the second step for 4140 plate fast delivery. BaoSteel makes the quality originals the best. And Otai Special Steel has our own quality inspection instrument. Hand-held spectrometer use on Chemical composition analysis per heat and conform to the standard . UT test to check the material inside quality. Hardness test to guarantee the requirement. Physical checking to ensure tolerance . All the special size requested by the customer we have our own cutting machines. Vertical band sawing machine, Horizontal sawmill. CNC Gas Cutting Machine, Plane milling machine. End face milling machine, Large die spotting machine. Make sure the size meeting customer’s tolerance.
3. The best service from Otai Special Steel was the last step to confirm the 4140 plate fast delivery. All the other difficult could be handle by Otai before shipment. The end-use guiding. Technical problems in the use of processing . Delivery problems. Shipping documents problems …… All the problems we could solve for you.
4. Know all of the Otai Special Steel and 4140 plate. Any interesting, please contact us directly.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com