THKLM Guide Carriage Block, Size 30, Four-Through-Hole Flange Type, 28 mm Rail, 45° Four-Way Equal Load, End and Side Seals — Block Only, No Rail

Product Description

What this part is

This is a THK LM Guide carriage block, model HSR30B — a four-way equal-load linear bearing block that runs on a 28 mm wide HSR size-30 LM rail. HSR is THK’s flagship full-ball linear guide: four rows of balls arranged at a 45° contact angle, so the block carries equal rated load in all four directions — radial, reverse-radial, and both lateral.

Block type and mounting holes

Within a single HSR size, the block types differ in the mounting holes, and the mountings are not interchangeable even though they share the same envelope and the same rail.

HSR30B: this part. Four ø9 mm through holes through the flange, on a 72 x 52 mm pattern, taking M8 bolts. THK’s detail-specification page for HSR 30B gives the block mounting direction as bottom-surface mount.

HSR30A: same envelope, with a tapped flange, 6 x M10 on 72 x 52 mm.

HSR30CA: the C-family block, tapped 6 x M10 and mountable from either the top or the bottom face.

HSR30R: a narrowed block, 60 mm wide rather than 90 mm, with 4 x M8 x 10 mm deep taps on a 40 x 40 mm pattern.

All four ride the identical HSR30 rail and carry the identical load ratings. The hole count and hole pattern are the distinguishing features between the types.

Block-only supply

This is the block on its own, supplied without an LM rail. THK marks standard LM Guide blocks and rails with matching serial numbers, and preload and running parallelism are set as a pair.

This part carries the (GK) designation. THK’s GK series offers interchangeable LM blocks and LM rails that combine freely provided they share the same model number. This block pairs with any HSR30 GK rail of matching accuracy and preload grade.

Condition

This is a new open-box block. The grease nipple and the locking bolt are absent from this piece. The greasing hole is a semi-standard specification on the HSR series, machined to order. The correct nipple for size 30 is B-M6F.

Decoding the designation

HSR: THK’s four-way equal-load full-ball LM Guide series.

30: size, corresponding to a 28 mm wide rail.

B: block type, flanged with four through holes.

1: THK’s coding field for the number of LM blocks used on the same rail. It is a model-number field rather than a pack quantity.

SS: end seal plus side seal. DD is double seal and UU is end seals only.

GK: the interchangeable block-only / rail-only series.

Published dimensions and ratings

Assembly height M: 42 mm. Block width W: 90 mm. Block length L, with UU or SS seals: 98 mm. Block body L1: 70.4 mm.

Mounting hole pattern B x C: 72 x 52 mm, with four ø9 mm through holes (dimension H).

Flange dimensions: t 18 mm, T 9 mm, T1 10 mm. Block shoulder K: 35 mm. N: 7 mm. E: 12 mm.

Mating rail width W1: 28 mm (±0.05). Rail height M1: 26 mm. W2: 31 mm.

Rail mounting hole pitch F: 80 mm. Rail hole d1 x d2 x h: 9 x 14 x 12 mm.

Basic dynamic load rating C: 40.5 kN. Basic static load rating C0: 53.7 kN.

Static permissible moment MA: 0.599 kN·m for one block, 3.1 kN·m for two blocks. Static permissible moment MB: 0.599 kN·m for one block, 3.1 kN·m for two blocks. Static permissible moment MC: 0.652 kN·m for one block.

Rolling elements: four rows of balls at a 45° contact angle, full complement retained by retainer plates.

Block mass: 1.1 kg. Rail mass: 4.8 kg/m.

Grease nipple specification: B-M6F. UU seal resistance: 7.80 N.

Service temperature: −15 to 80 °C. Standard grease: AFB-LF.

Radial clearance grades offered: Normal, light preload C1, medium preload C0.

Accuracy grades offered: Normal, H, P, SP, UP.

Rail mounting-hole cap: C8. Maximum standard rail length: 3000 mm, 2520 mm in stainless.

45° contact angle

The four-row 45° geometry sets the contact lines at 45° to one another, so capacity is identical in all four radial directions and moment stiffness is symmetrical. The rail runs on a wall, inverted or vertically at full rating, and a single block resists roll, pitch and yaw. The circular-arc groove geometry gives the HSR a self-adjusting characteristic that absorbs a degree of mounting-surface error.

A full-complement ball guide has balls touching one another in the circulation path, which runs warmer and noisier at high speed than a caged-ball design. Heavy-cutting machine tools are THK’s stated home for the HSR family.

Moment figures

MA and MB are quoted both for one block and for two blocks in close contact on the same rail. The two-block figure is roughly five times the one-block figure. Two blocks spaced along a rail react a moment as a couple between them, so capacity scales with the spacing.

Mounting data

Grease nipple specification for size 30: B-M6F.

An inner seal is available on sizes 30 and above as an option beyond the standard end and side seals. Any added contamination-protection accessory increases the overall block length L above the 98 mm quoted.

Balls are held by retainer plates, so the block retains its balls when it is slid off a rail.

Interchange guidance

Cross-references and alternative renderings of the same part: HSR30B1SS, HSR30B1SS(GK), HSR30B1SSGK, HSR-30B1-SS, HSR30-B1-SS, HSR 30 B1 SS, HSR30B, HSR-30-B, HSR30B1UU. Same size, different mounting: HSR30A, HSR30CA, HSR30R. Same block in stainless: HSR30BM. Long block, same cross-section and higher rating: HSR30LB (C 48.9 kN, C0 70.2 kN). Adjacent sizes: HSR25B, HSR35B.