Motor Starters vs. Contactors vs. Overload Relays: What Each One Does and Why You Need All Three
When a motor stops running, the first instinct is to find the part that looks
Availability:
1 in stock
Two-row TDO tapered roller bearing set, 3.875 x 7.125 x 4.125 in. One double cup, two cones and a cone spacer, four pieces, factory-set.
List Price
$390.12
1 in stock

1 in stock
On the Shelf & Ready to Ship
On all orders

No Risk, No Hassle
Also Available From:
| MFR / Brand | Bower |
|---|---|
| MPN | 779/774D/X1S |
| Model | 779 / 774D / X1S-779 |
| Bearing Type | Tapered Roller Bearing Cone |
| ID | 3.875 in (98.425 mm) |
| OD | 7.125 in (180.975 mm) |
| Width | 4.125 in (104.775 mm) |
| Material | Steel |
|---|---|
| Condition | New – Open box |
| Base Number | 779/774D |
| Industry Terms | TDO bearing; tapered double outer; double cup tapered roller bearing; two-row taper bearing set; cone spacer set; matched taper assembly; Bower double cup taper |
| Total Width | 4.125 in (104.775 mm) overall; cone inner ring width B 1.875 in each row |
| Condition Note | Made In USA, (2) 779 (1) 774-D (1) X1S-779, New Old Stock |
| Bore Shaft Size | 3.875 in (98.425 mm) |
| Mpn Variants | 779/774D/X1S; 779-774D-X1S; 779 774D X1S; 779/774D; 779-774-D; 774-D; 774D; X1S-779; X1S779; 779 |
| Compatible With Replaces | Piece list: 2 x cone 779, 1 x double cup 774-D, 1 x cone spacer X1S-779. Timken catalogue designation for the two-row assembly: 779/774D. |
| Arrangement Configuration | TDO (Tapered Double Outer) - two cones back to back in one double cup, separated by a ground cone spacer |
| Precision Class | Not specified |
| Series | 774 |
| Cage Material | Steel |
| Number Of Rows | 2 |
| Bore Type | Straight |
| Harmonization Code | 8482.20.00 |
| Design Units | Inch |
| Bearing Material | Steel |
| Part Number | 779/774D/X1S-779 |
| Cage Type | Stamped |
| Cross Reference 1 | Timken 779/774D (same two-row TDO assembly, Timken catalogue designation) |
|---|---|
| Cross Reference 2 | Timken 779 (cone component of this set) |
| Cross Reference 3 | Timken 774-D (double cup component of this set) |
| Cross Reference 4 | Timken X1S-779 (cone spacer component of this set) |
| Cross Reference 6 | Timken 779/772 (related size, single cup, one row, 1.875 in width) |
| Cross Reference 7 | Timken 777/774D, 778/774D, 782/774D, 783/774D (related sizes, same double cup, different bore) |
Bower 779/774D/X1S is a two-row inch-series tapered roller bearing set in the TDO configuration — Tapered Double Outer. Bore: 3.875 in (98.425 mm). Outside diameter: 7.125 in (180.975 mm). Overall assembly width: 4.125 in (104.775 mm). Cone inner ring width (B), each row: 1.875 in (47.625 mm). Series: 774.
779 is the cone. 774-D is the double cup: the D on a cup designates a one-piece double outer ring with two raceways, and it takes two cones. X1S-779 is the cone spacer, which sets the axial distance between the two cones and therefore fixes the internal setting of the pair. Design units: inch.
Four pieces in one set: two 779 cones, one 774-D double cup, and one X1S-779 cone spacer. Two rows. Rolling elements: tapered rollers. Cage: stamped steel. Bearing material: steel. Open, unsealed.
A TDO carries thrust in both directions and takes overturning moment, because the two rows sit back to back with their effective load lines diverging outward. That wide effective spread gives a TDO high moment stiffness in a short axial envelope, which is why the type is used in wheel hubs, sheave blocks, crane travel wheels and idler positions where one bearing has to locate the shaft completely. The X1S-779 spacer is ground to length, so the set arrives with its internal clearance or preload already established rather than being set on assembly.
The double cup mounts in a single straight housing bore and locates against one housing shoulder. Each 779 cone presses onto the shaft with the spacer between their backfaces. Lubrication: oil or grease. The set is matched: the two cones, the double cup and the spacer are ground as a unit and are kept together.
Searchable forms of the designation: 779/774D/X1S, 779-774D-X1S, 779 774D X1S, 774-D, 774D, X1S-779, X1S779, 779. Bower is a legacy tapered roller brand now within Timken, and the Timken catalogue designation for this two-row assembly is 779/774D. Related sizes on the same 774-D double cup and the same 7.125 in outside diameter take different cones: 777/774D at 3.75 in bore, 778/774D at 3.625 in bore, 782/774D at 4.125 in bore and 783/774D at 3.937 in bore. The 779/772 is a related size using a single cup, giving one row at 1.875 in width rather than two rows at 4.125 in.
$409.62
1 in stock
$409.62
1 in stock
Nine bearing and power transmission manufacturers raised list prices this
Maintenance is now 65% Slower, but it’s not a labor
When a motor stops running, the first instinct is to find the part that looks
From Caligula’s luxury fleet to modern factories, this is the story of how a single
When sourcing a replacement bearing, you will often find both Timken and SKF options for
Our team can locate, cross-reference, and source all parts.
Sort
Brand
Price
MPN
Categories