Kuna tofauti gani kati ya Ra na Rz?

Ra (arithmetical mean roughness) is the average of absolute profile deviations from the mean line over the evaluation length. Rz (maximum height) is the average of the five highest peaks and five deepest valleys within the evaluation length. Ra gives an overall average roughness, while Rz is more sensitive to individual peaks and valleys. Roughly, Rz ≈ 4×Ra for most machined surfaces.

Ninabadilijaje kati ya Ra na Rz?

A rough approximation is Rz ≈ 4×Ra, but the exact ratio depends on the surface profile and machining process. For precision work, use the ISO standard conversion tables. For general engineering, the ×4 factor provides a reasonable estimate.

N class (roughness grade) ni nini?

N classes (N1 through N12) are roughness grade numbers defined in ISO 1302. Each grade corresponds to a specific Ra value: N1=0.025 μm, N2=0.05 μm, N3=0.1 μm, up to N12=50 μm. They provide a simplified way to specify surface roughness on drawings.

Ra ya kawaida kwa uendeshaji wa machining ni ipi?

Ra values za kawaida: Lapping/superfinishing: 0.025–0.1 μm (N1–N3). Fine grinding: 0.2–0.4 μm (N4–N5). Normal grinding/fine turning: 0.8–1.6 μm (N6–N7). Rough turning/milling: 3.2–12.5 μm (N8–N10). Casting/forging: 25–50 μm (N11–N12).

Ra ipi inayohitajika kwa bearing seats?

Bearing seats kwa kawaida zinasomeka Ra 0.8–1.6 μm (N6–N7) kwa shaft na housing bore. Kwa precision bearings, Ra 0.4 μm (N5) au bora zaidi inaweza kuhitajika. Daima angalia maelezo ya mutengenezaji wa bearing.

Zana ya Uhandisi Isiyolipisha

Kibadili cha Ukali wa Uso

Badilisha kati ya Ra, Rz, roughness class (N1–N12), na CLA/AA microinch values. Inajumuisha maelezo ya surface finish na typical machining processes.

Ra ↔ Rz Class N1–N12 CLA / AA μin

Results

Ra (Arithmetical Mean Roughness)

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Rz (Maximum Height)

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Roughness Class

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CLA / AA

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Surface Description

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Typical Process

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Class	Ra (μm)	Rz (μm)	CLA (μin)	Maelezo	Typical Process
N1	0.025	0.1	1	Mirror finish	Superfinishing, lapping
N2	0.05	0.2	2	Mirror finish	Superfinishing, lapping
N3	0.1	0.4	4	Very smooth	Lapping, honing
N4	0.2	0.8	8	Smooth	Fine grinding, honing
N5	0.4	1.6	16	Smooth	Fine grinding
N6	0.8	3.2	32	Fine	Grinding, fine turning
N7	1.6	6.3	63	Fine	Turning, milling
N8	3.2	12.5	125	Medium	Turning, milling
N9	6.3	25	250	Medium rough	Rough machining
N10	12.5	50	500	Rough	Rough machining
N11	25	100	1000	Very rough	Casting, forging
N12	50	200	2000	Very rough	Uhauzaji, kusandika, kukata kwa mlangizo

Ra — Wastani wa Hesabu wa Ukali

Ra ni wastani wa hesabu wa maadili kamili ya kupotoka kwa wasifu kutoka kwa mstari wa katikati, inayopimwa juu ya urefu wa tathmini:

Ra ndio kigezo cha ukali kinachotumika sana duniani. Inatoa dalili ya jumla ya muundo wa uso lakini inaweza kufichua kilele au vimbirizi vya kibinafsi.

Rz — Urefu wa Juu Zaidi wa Wasifu

Rz ni wastani wa kina cha ukali cha kipengele cha sampuli tano mfuatano. Inahisi zaidi kilele na vimbirizi vya kiwango cha nje:

Ubadilisho wa Takriban

ℹ️ Note: The Rz ≈ 4×Ra approximation is a rough guide for typical machined surfaces. The actual ratio depends on the surface profile shape and machining process, and can range from 3 to 8.

Ubadilisho wa CLA / AA

CLA (Centre Line Average) na AA (Arithmetic Average) ni maneno ya zamani ya Ra, yaliyoonyeshwa kwa microinches. 1 μm = 39.37 μin.

⚠️ Important: Ubadiliwaji kati ya Ra na Rz ni wa takriban. Kwa matumizi ya muhimu, pima kigezo maalum kinachohitajika na mgawanyiko moja kwa moja.

Surface Roughness Converter | Ra ↔ Rz ↔ Class ↔ Finish

Published by Nikolai Shelkovenko on Febuari 15, 2026 Febuari 15, 2026

Results

Ra — Wastani wa Hesabu wa Ukali

Rz — Urefu wa Juu Zaidi wa Wasifu

Ubadilisho wa Takriban

Ubadilisho wa CLA / AA

Duka

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