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Tapered roller bearing NTN 4T-LM78349A†/LM78310A††
- Manufacturer Part Number
- 4T-LM78349A†/LM78310A††
- Brand
- NTNOfficial distributor
- Category
- Bearings
- Subcategory
- Tapered roller bearings
- Series
- J
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Description
NTN 4T-LM78349A†/LM78310A†† is a tapered roller bearing reference, within Bearings. Request a quote for 4T-LM78349A†/LM78310A†† via WhatsApp or email with the quantity you need; we respond promptly with lead time and equivalents.
NTN J series tapered roller bearings are components designed to support combined radial and axial loads. Their tapered roller and raceway geometry distributes the load over a larger contact surface than that of a ball bearing, making them suitable for applications with significant loads. They are used in equipment where precision and load capacity are critical, such as gearboxes, transmission shafts and industrial machinery in general. MR Accesorios Industriales sells this series for the Argentine market.
The designation of these bearings combines letters and numbers that identify the type, the dimension series and the internal design. For example, in 4T-LM78349A†/LM78310A††, the prefix 4T indicates a specific NTN execution, while LM78349A and LM78310A correspond to the cone and the cup respectively, with the suffix A indicating a design variant. The J series groups tapered roller bearings with standardized dimensional characteristics, and the suffixes can provide information about the contact angle, the heat treatment or the internal clearance. Understanding these codes is key to selecting the correct component.
In Argentine industry, NTN J series tapered roller bearings are used in a wide variety of applications: from gearboxes and reducers to wheel shafts, pumps, fans and mining equipment. They are also present in agricultural machinery, such as seeders and combine harvesters, where combined loads and demanding conditions require robust bearings. Their ability to support axial loads in both directions, when mounted in pairs, makes them versatile for different types of power transmission.
To correctly select a tapered roller bearing, take into account the radial and axial load it will have to support, the rotation speed and the environmental conditions. Mounting requires precise alignment and proper adjustment of the internal clearance, which can be regulated using shims or nuts. Lubrication, whether with grease or oil, must be appropriate for the operating temperature and speed. Sealing is essential to prevent contamination by dust or particles, and in critical applications it is recommended to use bearings with integrated seals or additional radial shaft seals.
NTN J series tapered roller bearings are interchangeable with those of other brands that follow the same dimensional and designation standards. When looking for a replacement, it is important to verify not only the main dimensions (bore, outer diameter and width) but also the contact angle and the internal clearance, since these factors affect performance. If the customer brings the code of another brand or an unidentified part, at MR Accesorios Industriales we can tell you the compatible equivalent and quote the appropriate option.
If you need an NTN J series tapered roller bearing, write to us via WhatsApp with the code or the measurements shown on your equipment. At MR Accesorios Industriales we will quote you promptly and advise you so that the selection is correct. We can also help you with lubrication and mounting accessories.
This description provides guidance on the product type. Check the configuration and dimensions of this reference.
Dimensions
Dimensions and tolerances: Send us the part number via WhatsApp and we'll confirm dimensions, sealing, and internal clearance against the manufacturer's data sheet.
Frequently Asked Questions
- What does the designation 4T-LM78349A†/LM78310A†† mean?
- The prefix 4T indicates an NTN execution. LM78349A identifies the cone (inner ring) and LM78310A the cup (outer ring). The suffix A indicates a design variant. This nomenclature allows each component of the bearing to be identified for mounting and replacement.
- How are tapered roller bearings mounted?
- They are normally mounted in pairs, with the cones facing each other, to support axial loads in both directions. It is essential to adjust the internal clearance according to the equipment specifications, using shims or lock nuts, and to verify alignment to avoid premature wear.
- What lubrication do you recommend for these bearings?
- Lubrication depends on speed, temperature and the environment. It can be with grease or oil, always following the equipment manufacturer's recommendations. It is important to maintain cleanliness and sealing to prevent the entry of contaminants that reduce the bearing's service life.

