# Boston Gear 30267184 842B-3.9K-M1 Helical Speed Reducer 3.9:1 Ratio - MROSupply.com

***Boston Gear 30267184 842B-3.9K-M1 helical speed reducer with 3.9:1 ratio. Helical gear design provides smooth, quiet operation for industrial power transmission applications. The 842B series delivers reliable speed reduction for conveyors, material handling, and general machinery drives.***



## Product details:

- Catalog number: 842B-3.9K-M1
- SKU: 45433
- Price: ***$1,239.85*** Each
- Shipping: ***FREE SHIPPING***  ON ORDERS OVER $100
- Typically Ships in: 1 day
- Brand: [Boston Gear](https://www.mrosupply.com/brands/boston-gear/)
- Category: 
    - [Solid Input Shaft Inline Helical Reducers](htts://www.mrosupply.com/speed-reducers/inlineconcentric-speed-reducers/inline-helical-speed-reducers/solid-input-shaft-inline-helical-reducers/)
    - [Inline Helical Speed Reducers](htts://www.mrosupply.com/speed-reducers/inlineconcentric-speed-reducers/inline-helical-speed-reducers/)
    - [Inline/Concentric Speed Reducers](htts://www.mrosupply.com/speed-reducers/inlineconcentric-speed-reducers/)
    - [Speed Reducers](htts://www.mrosupply.com/speed-reducers/)
- Unit of measure: each
- Weight: 25.100 lb
- Technicall support: contact supplier for technical support on 800-626-2120


## Product images:
- https://static.mrosupply.com/images/noimage.webp


## Product documents / software:

- [Catalog Product Section](https://documents.mrosupply.com/product_documents/D0/D02379/p-1485-bg_800b_in-line_helical.pdf)
- [Engineering Data](https://documents.mrosupply.com/product_documents/D0/D02637/p-1485-bg_engineering-section_HDosJBH.pdf)
- [Full Catalog](https://documents.mrosupply.com/product_documents/D0/D02637/p-1485-bg_fKcoPkR.pdf)
- [Installation & Operation Manual](https://documents.mrosupply.com/product_documents/D0/D02637/p-3010-bg_40ahQ0b.pdf)

## Product's reviews:
- Gear box oil - This has been very hard to find. It’s the oil spec’ed for my 1950s Rockwell wedge bed planer gear box. I haven’t found it anyplace else.
- Na40 - Fast shipping!!! Great to do business with.
- Shaft output is reversible - Description should say that shaft is reversible. Other than that perfect fit. Good communication from the shipping folks.
- 12d.p. 14t spur gear - This item was closer to exactly what I needed than I had thought possible to find in the last 75 or so years. quite affordable, too. I almost didn't look, but when I did, there it was. I had in hand in just a couple of days.